ZIMONYI, I. The origins of the Volga Bulgarians. Studia Uralo-altaica, [S. l.], v. 32, p. 1–211, 1990. Disponível em: https://ojs.bibl.u-szeged.hu/index.php/stualtaica/article/view/13553. Acesso em: 5 may. 2024.