Klejn, Zbigniew. “The Dispute over the Origins of the Proto-Bulgarians and Gagauz ”. Balcanica Posnaniensia. Acta et studia 14 (December 31, 2007): 67–74. Accessed August 4, 2026. https://pressto.amu.edu.pl/index.php/bp/article/view/52829.