PENTEK, Zdzisław. Vlachs and Cumans in Bulgarian service under the Asen dynasty. Balcanica Posnaniensia. Acta et studia, [S. l.], v. 14, p. 125–134, 2007. DOI: 10.14746/bp.2007.14.9. Disponível em: https://pressto.amu.edu.pl/index.php/bp/article/view/52832. Acesso em: 2 oct. 2026.