Ahangar, A. & Shahsavar, M. (2009). A study of sociolinguistic variables of Persian in Nehbandani Dialect: Consonants. Language and Linguistics, 5 (10), 71-114 (In Persian).
Ahangar, A. & Shahsavar, M. (2019). The effect of social variables on vowel variations of sociolects of Persian in Nehbandan. Language Studies, 6 (13), 7- 44 (In Persian).
Bailey, G. (2002). Real and apparent time. In J.K. Chambers, P. Trudgill, & N. Schilling-Estes (Eds.), The Handbook of Language Variation and Change (pp. 312-332). U.K: Wiley
Boberg, Ch. (2004). Ethnic patterns in the phonetics of Montreal English. Journal of Sociolinguistics, 8 (4), 538-568.
Eckert, P. (2000). Linguistic variation as social practice. Massachusetts and Oxford, U.K.: Blackwell.
Fishman, J.A. (1969). National languages and languages of wider communication in the developing nations. Anthropological Linguistics, 11 (4), 111-135.
Fishman, J.A. (1972). The sociology of language. In P.P. Giglioli (Ed.), Language and Social Context (pp. 45-58). Harmondsworth: Penguin.
Fukushima, S. (2003). Requests and culture. Germany: Peter Lang.
Herzog, M. (1964). The Yiddish language in Northern Poland: Its geography and history. Ph.D. Dissertation in linguistics, Columbia University.
Hudson, R. A. (1996). Sociolinguistics (2nd ed.). New York: Cambridge University Press.
Labov, W. (1963). The social motivation of a sound change. Word, 19 (3), 273-309.
Labov, W. (1966). The social stratification of English in New York City. Washington: Center for Applied Linguistics.
Labov, W. (1972). Sociolinguistic patterns. Philadelphia: University of Pennsylvania Press.
Labov, W., Ash, Sh., & Boberg, Ch. (2006). The Atlas of North American English: Phonetics, phonology and sound change. A multimedia reference tool. Berlin, New York: Mouton de Gruyter.
Modaressi, Y. (1978). A sociolinguistic investigation of Modern Persian. Ph.D. Dissertation in linguistics, University of Kansas.
Rezapour, E. (2017). Interaction of syntax and sociolinguistics: A social study of some Persian syntactic structures based on Labov's theory. Language Studies, 9 (22), 77- 105 (In Persian).
Sama'eneya, S. (2005) The study of some social and geographical changes of Persian in Sabzevar based on Labov's theory. M.A. Dissertation in linguistics, University of Sistan and Baluchestan (In Persian).
Schilling-Estes, N. (2004). Constructing ethnicity in interaction. Journal of Sociolinguistics, 8 (2), 163-195.
Tagliamonte, S.A. (2016). Teen talk. The language of adolescents. Cambridge: Cambridge University Press.
Wardhaugh, R. (1986). An introduction to sociolinguistics. U.k: Blackwell publications.
Wolfram, W. (2006). Variation and language. In K. Brown (Ed.), Elsevier Encyclopedia of Language and Linguistics (pp. 333-341). Oxford: Elsevier.
Zandi, B., Nasiri, P., & Radniri, E. (2015) A sociolinguistic study of diglossia in Ardabil. Linguistics and Khorasan dialects, 7 (13), 89- 107 (In Persian).