CC BY
35The syntax of Kazakh-Russian intrasentential code-switching in reported clauses
Research Article
Timur Akishev
Abstract
The given study represents an interpretive approach to the syntax of Kazakh-Russian intrasentential code-switching. It encompasses a review of the literature on code-switching as a phenomenon involving certain syntactic processes, a description of the general linguistic peculiarities of Kazakh and Russian and their syntactic systems, and an analysis of the syntactic nature of intrasentential code-switching between these two languages occurring in reported clauses. The contribution that this study aims to make is of theoretical nature and it is associated with the fact that the syntax of Kazakh-Russian code-switching has not been fully described from the standpoint of generative syntax.
Received:
29 February 2020 Reviewed: 12 March 2020 Accepted: 14 March 2020 Published: 7 June 2020
UDC: 8136
Keywords
bilingualism; code-switching; word order; Kazakh language; Russian language; reported clauses
Department of Modern Languages, The University of Mississippi, University, MS 38677 USA
Corresponding author:
Timur Akishev (Mr.), tbakishe@go.olemiss.edu
For citation:
Akishev, Timur. 2020. "The syntax of Kazakh-Russian intrasentential code-switching in reported clauses." Language. Text. Society 7 (1). https://ltsj.online/2020-07-1-akishev.
Language. Text. Society
Vol. 7 No. 1, 2020 ISSN 2687-0487
Introduction
Bilingualism, or the knowledge and command of two languages, is a linguistic phenomenon that can be encountered almost anywhere in the world. When speakers of a certain language acquire a language that is not native for them, they learn to use the inherent linguistic system of that language to explicate their intentions in the process of communication.
The speech of bilingual speakers is characterized by the presence of a special characteristic referred to as code-switching. This characteristic is defined as the 'use of elements from two languages in the same utterance or in the same stretch of conversation' (Paradis, Genesee, and Crago 2011, 88). Thus, the features of code-switching in the speech of bilinguals can be manifested either across a number of linguistic constructions or in terms of a single utterance. The given study deals with this single-utterance type, which is referred to as intrasentential code-switching. As seen from the term, this type of code-switching occurs at the sentence level, with the language shift made typically in the middle of a sentence without any interruptions made by the speaker that would imply the shift (Appel and Muysken 1987). The intrinsic peculiarities of this type of code-switching have always been of interest to researchers working in the various branches of linguistics, among which are Gumperz (1982), Myers-Scotton (1993), Milroy and Muysken (1995), Macswan (1999) and many others.
The given study aims to describe the syntactic nature of intrasentential code-switching of Kazakh-Russian bilingual speakers. Although it is a new research trend whose theoretical and practical frameworks are still in need of development, there are other instances of related languages whose code-switching has been extensively studied in terms of syntactic theory. It is important to note that the implementation of this study serves as a preparatory stage of the research to be conducted in the future, which is why it only focuses on a review of the basic theoretical conceptions of the syntaxes of the languages in question and how they interact in terms of code-switching.
As a competent speaker of both Kazakh and Russian, I intend to make a personal contribution to the expansion of the existing body of knowledge on the syntactic relations occurring between these languages in the code-switching of bilingual speakers. While it was possible for me to find a solid research background for the study of the Russian language in the field of generative syntax to base my assumptions and hypotheses about this language on, the problem arose when I tried to look up different sources on the syntax of my native language. When I did the search, it was possible to find only a few research papers discussing the Kazakh language from the standpoint of generative syntax that are not in any way connected with the topic of this study. What I subsequently realized is that the generative syntax of the Kazakh language is a new and unresearched field. Therefore, I consider this study an interesting challenge inasmuch as I will not only try to describe the complex syntactic nature of code-switching occurring between the two languages in question here, but also be, with all humility, among the trailblazers of Kazakh generative syntax, which is a huge responsibility that I am more than willing to undertake.
Importantly, this study will primarily focus on finding out what it is exactly that determines the word order, namely, the ordering of V and O, in Kazakh-Russian code-switched reported clauses including Russian relative pronouns and their Kazakh agglutination-based and verb-related suffixival counterparts. To understand that, I plan to describe these languages in general, analyze their word order characteristics, discuss their generative syntax research background, if any, and hypothesize on the phenomenon of intrasentential code-switching occurring between Kazakh and Russian syntactic patterns in reported clauses, a dependent clause type that indicates what someone said or thought and is formed with the help of a certain language-specific complementizer. Russian relative pronouns and their Kazakh suffixival counterparts are the complementizers whose syntactic peculiarities are studied in terms of the research conducted.
The given paper consists of an introduction section discussing the scope of this study and giving a brief description of the basic notions, a literature review section discussing the syntactic characteristics of these languages in general and in terms of a number of papers, and a hypotheses section providing the implications and suggestions for further research and representing the synthesis of the most topic-relevant ideas from the papers discussed in the review of the literature. At this stage, however, the given study does not include a methodology section, a discussion section, a results section, and a conclusion section for the reasons given above. Future research on this topic will provide the necessary information on what linguistic data will be analyzed and from which syntactic perspective I intend to look at the phenomenon of Kazakh-Russian intrasentential code-switching.
Importantly, the examples used in this paper are fabricated and derived from my own observations. As a bilingual and a linguist, I have frequently encountered real-life linguistic constructions similar to the examples presented. Unfortunately, there is currently no comprehensive database of examples of use of this mixed Russian-Kazakh code. Due to this fact, I have decided to develop examples which could reflect the gist of this phenomenon in its entirety. Taking into account the fact that my research supervisor is American, I have developed stylistically and culturologically neutral examples, preserving the typical morphology and word order in constructions of such a mixed type.
Literature review
The given section encompasses a source-based description of the peculiarities of the syntactic systems of the two languages, and a brief discussion of the article connected with the topic of the study. First of all, it is important to discuss the linguistic characteristics of the Russian language inasmuch as it is better and more extensively described from the perspective of generative syntax, which I realized after doing a bibliography search. Russian, an East-Slavic language pertaining to the family of Indo-European languages and spoken all over the world, is a synthetic language with flexible word order in which the SVO pattern is generally considered as predominant (Vereshchagin 1974).
The flexibility of the Russian word order allows for a number of alterations in the positioning of S, V, and O. These alterations are generally considered as stylistic devices employed with a view of placing an emphasis on certain constituents within the structure of a clause (Gasparov 1978). Thus, in terms of a simple SVO sentence, as the examples below demonstrate, the following word order alterations are possible in Russian:
(1) Subject-initial positioning
S V O a. Madina chitayet knigi.
Madina reads books 'Madina reads books.'
(2) Verb-initial positioning
V S O
a. Chitayet Madina knigi.
Reads Madina books 'Madina reads books.'
(3) Object-initial positioning
O S V a. Knigi Madina chitayet.
Books Madina reads 'Madina reads books.'
S O V b. Madina knigi chitayet.
Madina books reads 'Madina reads books.'
V O S b. Chitayet knigi Madina.
Reads books Madina 'Madina reads books.'
O V S b. Knigi chitayet Madina.
Books reads Madina 'Madina reads books.'
These examples show that there are six different alternatives as to the positioning of S, V, and O elements within the structure of a clause. The placement of constituents may differ, which is why there may be subject-initial, verb-initial, and object-initial constituent positioning in Russian (Sirotinina
2014). This flexibility in word order is important to bear in mind when dealing with the syntax of the Russian language in that the placement of clause constituents may vary. Although this study deals only with the simple and straightforward SVO pattern in reported clauses that will be discussed in depth later on in the paper, it is still important to remember the various ways in which clauses in Russian can be constructed because the ordering of constituents has considerable influence on the meanings incorporated in utterances.
In terms of syntax, reported clauses in Russian are dependent (embedded) clauses inserted into the structure of a main clause based on the principle of subordination. An embedded reported clause serves as a complement (CP) of the main clause verb resting in the tense phrase (TP) preceding it and including the information on the original source of the utterance, i.e. the original speaker (Starodumova 2005). Importantly, the main clause subject-and-verb pattern is not an independent clause and is considered simply a part of the main clause which includes both this pattern and the embedded clause. It is very common, though erroneous, to refer to this pattern as the main clause in Russian linguistics (Borras and Christian 1971). The adjunction of an embedded clause to the main clause subject-and-verb pattern is performed with the help of different relative pronouns, the choice of which depends on what meaning is incorporated into the reported utterance by the speaker (Starodumova 2005).
The given study deals only with Russian reported clauses containing the relative pronoun chto, which is the equivalent of the English 'that'. It is important to note that chto is always preceded by a comma that separates the reported clause from the main clause TP pattern reflecting the act of reporting (Starodumova 2005). The example below presents the structure of a reported clause including this relative pronoun in the role of a complementizer:
(4) Madina skazala, chto chitayet knigi.
[CP1 [TP1 S V [cp2 C [tp2 (S) V O ]]]]
[CP1 [TP1 Madina skazala,[CP2 chto [TP2 (ona) chitayet knigi]]]] Madina said that (she) reads books
'Madina said that she reads books.'
In this example, CP1 is the main clause. TP1 includes the subject of the main clause Madina and the main verb skazala, the complement (or object) of which is the embedded reported clause CP2 chto (ona) chitayet knigi formed with the help of the complementizer chto that requires the structure within TP2 to be SVO. However, it is possible, even advisable in Russian, to omit the subject of the embedded clause without affecting the originally incorporated semantic meaning of the utterance. Importantly, subject omission is advisable only in the case that the reporting agent (the subject of the main clause) and the agent whose action is reported (the subject of the embedded clause) are one and the same person (Starodumova 2005).
Another possibility is that there might be a special semantic emphasis in the embedded clause on the agent performing the reported action placed by the same agent reporting it in the main clause TP, in which case there is no omission of the subject (Starodumova 2005):
(5) Madina skazala, chto ona chitayet knigi.
[CP1 [TP1 S V [cp2 C [tp2 S V O ]]]]
[CP1 [TP1 Madina skazala, [CP2 chto [TP2 ona chitayet knigi]]]] Madina said that she reads books
'Madina said that she reads books.'
In the example 5, the speaker named Madina emphasizes the fact that it is she who reads books. This structure, however, is impossible to distinguish from another possible pattern in which the speaker Madina refers to the action performed by another, though unnamed, female person inasmuch as these constructions are structurally identical. Thus, it is possible to infer that if the subject of the main clause is the agent of the reported-clause action who does not emphasize the fact that this action is performed by themselves, it is, again, advisable to omit the subject of the embedded clause in order to avoid confusion with another possible pattern that has the identical structure and word order.
It is therefore obvious that there is no subject omission in embedded reported clauses in the case that the agent performing the reported action is not the same person as the agent reporting it (Starodumova 2005). In the example below, the agent reporting the action is still a female person Madina, while the agent whose action is reported is an unnamed male person:
(6) Madina skazala, chto on chitayet knigi.
[CP1 [TP1 S V [cp2 C [tp2 S V O ]]]]
[cpi [tpi Madina skazala, [cp2 chto [tp2 on chitayet knigi]]]]
Madina said that he reads books
'Madina said that he reads books.
Thus, it is possible to infer that the word order of Russian reported clauses is a complex phenomenon whose characteristics are important to bear in mind in the analysis of clause structure. It is pertinent to note that the given study focuses on the discussion of Russian reported clauses including the complementizer chto and omitting their subjects (the agent performing the reported action) for the reason that they coincide with the subjects of the main clause (the agent reporting the action).
Having looked at the peculiarities of the Russian language, its word order and syntax, let us now turn to those of Kazakh. This language belongs to the Kipchak branch of the Turkic family of languages and is spoken in Kazakhstan, Russia, China and a number of other countries. It is an agglutinating language with a strictly fixed SOV word order with the verb resting in the clause-final position (Krueger 1980). However, it is possible, as it is in Russian, to change the positioning of the constituents with a view of placing an emphasis on one of them. There are two alternatives as to the positioning of the S, O, and V elements within a clause, as the following examples demonstrate:
(7) Verb-final positioning
S O V a. Madina kitap oqidy.
Madina books reads 'Madina reads books.'
(8) Object-final positioning
S V O a. Madina oqidy kitap.
Madina reads books 'Madina reads books.'
These examples show that there are only two possibilities as to the placement of the constituents within a simple clause. The standard positioning is, as has been mentioned, verb-final. The object-final positioning within a clause signifies the emphasis placed on the object (Muhamedowa 2016). Importantly, the given study will only consider the syntax of the standard SOV constituent positioning within reported clauses.
In Kazakh, the subject of the main clause precedes the embedded reported clause that serves as an object of the main clause verb that follows it, which means that the structure of the main clause is SOV (Muhamedowa 2016). The structure of the reported clause is, however, simply OV, which means that the subject is omitted. The omission of the subject is required because the suffixes attached to the reported-clause verb already manifest the characteristics of the subject, which means that this verb is
nominalized to a certain extent (Muhamedowa 2016). What is more, due to the fact that the subject is obligatorily omitted, there is no possibility of the reporting agent placing an emphasis on their own performing of the reported action.
Reported clauses in Kazakh are constructed without the use of relative pronouns. This means that there are no separate-word complementizers in this type of clauses (Muhamedowa 2016). While the Russian language has these separate-word complementizers, it is quite possible to assume that Kazakh morphology requires the agglutination-based complex verb structure to include them. Thus, the transformation of a Kazakh verb in the process of construction of a reported clause may imply the placement of the complementizer inside the verbal construction, which is why the complementizer can be considered as part of the reported clause TP:
(9) Madina kitap oqitynyn aitty.
[CP1 [TP1 S [cp2 [tp2 O V+C ]] V ]]
[cp1 [tp1 Madina [cp2 [tp2 kitap oqitynyn]] aitty]] Madina books reads-that said
'Madina said that she reads books.'
This structure in 9 may seem simplistic, and it is possible to simply state that in Kazakh the complementizer is part of the verb in TP2, thus treating the form oqitynyn as including the unspecified Kazakh equivalent of the English complementizer that or the Russian chto. However, things are more complex than this. The element oqitynyn can be morphologically divided in the following way: oqityn-y-n, in which oqityn is a Present Participle form, -y is a possessive noun-specific ending representing the fact that the action is done single-handedly by a third person, and -n is an Accusative Case suffix. What appears to be true here is that it is exactly the compound suffix -yn that possesses the characteristics of a complementizer. Thus, while we can leave the Present Participle form oqityn in its original position, the compound suffix -yn can be moved out of TP2 into CP2 to serve as a complementizer that is syntactically (but not morphologically) separate from the verb, as is the case with the Russian complementizer chto, though the positioning of -yn is not the same as that of chto:
(10) Madina kitap oqitynyn aitty.
[cP1 [tP1 S [cP2 [tP2 O V ] C ] V ]]
[cp1 [tp1 Madina [cp2 [tp2 kitap oqityn ] y-n ] aitty]] Madina books reading 3SG POSS-ACC said
'Madina said that she reads books.'
In 10, the suffixival verb-dependent complementizer -yn is syntactically separated from the bare verbal form oqityn and is moved out of TP2, where it rested in 9, to serve as an independent complementizer. Therefore, it is now possible to claim that in Kazakh reported clauses it is exactly this suffixival C that determines the ordering of O and V inside the reported-clause TP in that C follows it and is followed by the main clause verb with which it, morphologically merging with the bare verb form in TP, interacts on the basis of a nominalizing relationship.
My assumption that C determines the ordering of V and O is based on the hypothesis proposed by Jansen, Muller and Muller in their article Code-switching between an OVand a VO language (2012). This article focuses on the syntactic analysis of intrasentential code-switching in French, Italian, Spanish and German bilingual speakers. The principal purpose of the article is to find out what determines the syntax of code-switched OV and VO utterances and subordinate clauses (Jansen et al. 2012).
The main hypothesis propounded in the article is that the language of the complementizer determines the ordering of the V and O elements in code-switched utterances. The authors argue that the complementizer is 'decisive for the syntax of code-switching in subordinate clauses' (2012, 337). They also suggest that this way of thinking is applicable to monolingual utterances as well. Thus, their assumption that the complementizer determines the word order in monolingual subordinate clauses resonates with my previous claim that in Kazakh reported clauses the verb-dependent suffixival complementizer is responsible for the placement of O and V. This appears to be a more well-grounded argument for why the word order in Kazakh reported clauses is OV than the one I provided earlier. What Jansen et al. also posit is that the syntactic characteristics of code-switched utterances are influenced by the language of the head C, regardless of the language incorporated in T or V (2012, 337). This way of thinking can be applied to my analysis of Kazakh-Russian code-switched reported clauses in the following section.
Discussion
The given section provides an analysis of the syntactic structure of Kazakh-Russian code-switched utterances and presents the hypotheses based on that analysis which will be tested in terms of future research.
First of all, let us discuss an example of a Kazakh-Russian code-switched reported clause. The following utterances will be mixed: the Kazakh Madina kitap oqitynyn aitty and the Russian Madina skazala, chto chitayet knigi. The code-switching of these utterances most likely results in the structure Madina knigi chitat' etetinin aitty. The subject and the verb of the main clause are Kazakh, while the object and the verb in the reported clause are Russian. What is more, the Russian complementizer chto is omitted, which implies the presence of a certain Kazakh complementizer. Importantly, the third person singular form of the Russian lexical verb, chitayet, is infinitivized and followed by a Kazakh nominalized auxiliary verb etu 'to do' in its Present Participle form etetin extended by the compound nominal suffix -in, in which -i is a third person possessive suffix, and -n is an Accusative Case suffix. The syntactic structure of this utterance is given below in 11 and it is based on the analysis in 10. It is important to note that for the purpose of making the example more understandable in terms of distinguishing between the languages, the Russian-language reported-clause elements are italicized.
(11) Madina knigi chitat' etetinin aitty.
[cP1 [tP1 S [cP2 [tP2 O V Vaux] C ] V ]]
[cp1 [tp1 Madina [cp2 [tp2 knigi chitat' etetin] i-n ] aitty]]
Madina books readINF doing 3SG POSS-ACC said
'Madina said that she reads books.'
If we do not take into consideration the presence of the Kazakh auxiliary verb form etetin inside the reported-clause TP2, the word order of this construction is OV, which means that in the process of code-switching the resulting utterance acquired the Kazakh word order peculiarities. However, it is important to determine what exactly it is that the element etetin does. Apparently, it acquires the nominalization characteristics that the Russian verb should acquire. Why the Russian verb is infinitivized is, however, not a matter of the syntactic analysis conducted in terms of this study. Furthermore, disregarding the presence of the Kazakh auxiliary verb in an all-Russian TP2 looks like an easy way out, whereas the full structure inside TP2 is actually OVVaux, which appears to be overly complex and redundant. What is possible to do here is move this Kazakh auxiliary verb form out of TP2 into CP2, attach its rightful suffixes to it, and treat it as an independent-word complementizer. In 12,
the structure of TP2 is simply OV, which is required by the now-independent Kazakh nominalized complementizer etetinin:
(12) Madina knigi chitat' etetinin aitty.
[cp1 [tp1 S [cp2 [tp2 O V ] C ] V ]]
[CP1 [TP1 Madina [CP2 [TP2 knigi chitat' ] etetin-i-n ] aitty]]
Madina books readINF doing-3SG POSS-ACC said
'Madina said that she reads books.'
As seen in the example above, the ordering of O and V is determined by the Kazakh independent-word complementizer. Although the Russian lexical verb inside TP2 remains infinitivized, the ordering of the elements is now simple and straightforward. Furthermore, there may be a morphosyntactic explanation for why the word order inside this code-switched utterance is exactly OV: it is obligatory in Kazakh that the auxiliary verb etu be preceded by the lexical verb, with no possibility of placing anything in between these elements. Therefore, it is impossible to place the object after the lexical verb, which leaves us with the OV pattern. What is more, although the lexical verb is Russian, it is the language of the complementizer that determines the word order here, and this language is SOV, which is why there is only one possibility of ordering the O and V elements within this code-switched reported clause.
Thus, the main hypothesis developed in this paper is that in Kazakh-Russian code-switched reported clauses the language of the complementizer determines the ordering of O and V, with this complementizer being a syntactically independent unit which, although connected with the lexical verb inside the reported-clause TP, acts as a separate-word complementizer that possesses the nominalized characteristics of person, possessiveness, and case.
To test this hypothesis in terms of further research, I intend to develop a more comprehensive methodological approach to studying the syntax of Kazakh-Russian code-switching in reported clauses. I intend to choose actual, and not fabricated, linguistic data to analyze on the basis of a certain algorithm, which will enable me not only to better describe the linguistic nature of code-switching between these two languages, but also come up with a more detailed explanation of the syntactic phenomena occurring in both of them, especially my native language, Kazakh, whose generative syntax is a new research field.
Conclusion
This research paper has in many ways informed my approach to the analysis of Kazakh-Russian language contact and second language generative syntax.
One of the limitations of the study is its sole focus on the analysis of the syntactic peculiarities, especially the alterations of word order and the verb morphology of the Kazakh clause. According to the study, the process of code-switching has caused the infinitivization of the Russian-language elements inserted into the Kazakh utterance. Due to the fact that the Kazakh language has no direct equivalents of the relative pronoun "chto", the Kazakh verb, especially its agglutinative morphology, assumes the functions of the complementizer. Importantly, other linguistic aspects of code-switching between these languages will be considered holistically in terms of further research.
There is hypothetically a direct link between the code-switched syntax of the Kazakh clause and the agglutinative nature of Kazakh verb morphology. As has been said, there is no explicit complementizer of the Russian "chto", so the verb construction assumes that role. It is possible that the presence of an agglutinated, and rather implicit, complementizer prevents the occurrence of the
Russian "chto" in the code-switched reported clause. If "chto" were to occur in such a clause, the word order would be somewhat different. An important role is played by the process of mixing the verb and verb-based elements of both languages. What this role is and why this process of code-switching occurs, however, are the questions that need to be answered through more qualitative and quantitative research on this topic.
Applying the theories of generative syntax, this study has attempted to describe the peculiarities of code-switching occurring within utterances, or intrasentential code-switching. The results can be replicable and applied in different studies on the syntax of Kazakh-Russian bilingualism, as well as generative-syntax approaches to understudied languages, such as Kazakh. Further research must focus on the operationalization of Chomskian syntax theories to the study of these languages' phrase and clause structure, as this may provide interesting findings about the intrinsic peculiarities of both languages that we may not be aware of yet.
References
Appel, Rene, and Pieter Muysken. 1987. Language contact and bilingualism. London ; Baltimore, MD: E. Arnold.
Borras, Frank Marshall, and Reginald Frank Christian. 1971. Russian syntax: aspects of modern Russian syntax and vocabulary. 2nd ed. Oxford: Clarendon Press.
Gasparov, Boris Mikhailovich. 1978. "Ustnaia rech' kak semioticheskii obyekt" [Spoken language as a semiotic object], in "Lingvisticheskaia semantika i semiotika. I. Semantika nominatsii i semiotika ustnoi rechi" [Linguistic semantics and semiotics. I. Semantics of nomination and semiotics of spoken language]. Acta et Commentationes Universitatis Tartuensis 442:63-112. (in Russian)
Gumperz, John Joseph. 1982. Discourse strategies. Studies in interactional sociolinguistics 1. Cambridge [Cambridgeshire]; New York: Cambridge University Press.
Jansen, Veronika, Jasmin Muller, and Natascha Muller. 2012. "Code-Switching between an OV and a VO Language: Evidence from German-Italian, German-French and German-Spanish Children." Linguistic Approaches to Bilingualism 2 (4): 337-78. https://doi.org/10.1075/lab.2A01jan.
Krueger, John Richard. 1980. Introduction to Kazakh. Bloomington: Indiana University Press.
MacSwan, Jeff. 1999. A minimalist approach to intrasentential code switching. Outstanding dissertations in linguistics. New York: Garland Publishing.
Milroy, Lesley, and Pieter Muysken, eds. 1995. One speaker, two languages: Cross-disciplinary perspectives on code-switching. Cambridge [England]; New York: Cambridge University Press.
Muhamedowa, Raihan. 2016. Kazakh: A Comprehensive Grammar. Routledge Comprehensive Grammars. London; New York: Routledge.
Myers-Scotton, Carol. 1993. Social motivations for codeswitching: Evidence from Africa. Oxford studies in language contact. Oxford: Clarendon Press.
Paradis, Johanne, Fred Genesee, and Martha B. Crago, eds. 2011. Dual language development and disorders: A handbook on bilingualism and second language learning. 2nd ed. Baltimore, MD: Paul H. Brookes Publishing Company.
Sirotinina, Olga Borisovna. 2014. Poriadokslov v russkom iazyke [Word order in Russian]. Moscow: URSS, 2014. (in Russian)
Starodumova, Elena Alekseevna. 2005. Sintaksis sovremennogo russkogo iazyka [Modern Russian syntax]. Vladivostok: Far Eastern Federal University Press. (in Russian)
Vereshchagin, Evgenii Mikhailovich. 1974. Russkii iazyk v sovremennom mire [Russian in today's world]. Moscow: Nauka. (in Russian)
Acknowledgments
The author declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. The author received no financial support for the research, authorship and/or publication of this article.
Copyrights
Copyright for this article is retained by the author, with publication rights granted to the journal.
This open access article is distributed under a custom license: freely available to download, save, reproduce, and transmit for noncommercial, scholarly, and educational purposes; to reuse portions or extracts in other works—all with proper attribution to the original author(s), title, and the journal. Commercial use, reproduction or distribution requires additional permissions.
