KIJAS, Artur. Rus’-Bulgarian relations up to the fifteenth century, with particular emphasis on cultural contacts. Balcanica Posnaniensia. Acta et studia, [S. l.], v. 2, p. 113–124, 1985. DOI: 10.14746/bp.1985.2.8. Disponível em: https://pressto.amu.edu.pl/index.php/bp/article/view/54819. Acesso em: 4 oct. 2026.