Jones, Charles & James S Levine, ???-?? . 2010. Conditions on the Formation of Middles in Russian. Journal of Slavic linguistics 18. (Journal Of Slavic Linguistics). 291?336.

Ohala, John J, ??? . 1993. The phonetics of sound change. ? , Historical linguistics: Problems and perspectives, 237?278. (Historical Linguistics: Problems And Perspectives). London-New York: Longman.