MADGEARU, Alexandru. The Competition for Cumania between Hungary and Bulgaria (1211–1247). Studia Ceranea, Poland, v. 12, p. 699–723, 2022. DOI: 10.18778/2084-140X.12.28. Disponível em: https://www.czasopisma.uni.lodz.pl/sceranea/article/view/15609. Acesso em: 25 may. 2026.