MLA

Tikhov, N. Ocherk Grammatiki Zapadno-Bolgarskago nari︠e︡chīi︠a︡ Po Sborniku Bolgarskikh pi︠e︡sen V. V. Kachanovskago. Tip. Imp. universiteta, 1891. https://collections.library.yale.edu/catalog/30107304.

APA, 6th edition

Tikhov, N. (1891). Ocherk grammatiki zapadno-bolgarskago nari︠e︡chīi︠a︡ po Sborniku bolgarskikh pi︠e︡sen V. V. Kachanovskago. Tip. Imp. universiteta. https://collections.library.yale.edu/catalog/30107304.