Chernogorova, Tsvetanka. “Perceptual Assimilation of SSBE Vowels by Tertiary-Level Bulgarian Students”. Philologia 11, no. 1 (May 16, 2021): 11–19. Accessed April 11, 2025. https://philologia.org.rs/index.php/ph/article/view/philologia-2013-11-11-2.