ČEPAR, M. Rumjana Koneva: Ivan Šišmanov i obedinena Evropa. Journal for Foreign Languages, [S. l.], v. 5, n. 1-2, p. 293–296, 2013. DOI: 10.4312/vestnik.5.293-296. Disponível em: https://journals.uni-lj.si/Vestnik/article/view/1060. Acesso em: 26 nov. 2022.