STOITCHKOV, Vallery. New data on the subject of development of the castle of Almus and its territory. Balcanica Posnaniensia. Acta et studia, [S. l.], v. 7, p. 251–258, 1995. DOI: 10.14746/bp.1995.7.19. Disponível em: https://pressto.amu.edu.pl/index.php/bp/article/view/54215. Acesso em: 4 oct. 2026.