SCHREINER, P. Angelov, Petŭr: Bŭlgarskata srednovekovna diplomacija. Südost-Forschungen, [S. l.], v. 1, n. 1, p. 407–408, 2021. Disponível em: http://bsb0sit-zepweb01.bsb.lrz.de/portal/index.php/sof/article/view/8650. Acesso em: 23 nov. 2024.