JELEV, G.; STEFANOVA, D.; STEFANOV, P.; BONEV, D.; STOYANOVA, A.; CHILAKOVA, D. GIS research project on karst in Bulgaria. Annual of Natural Sciences Department, [S. l.], v. 5, p. 52–58, 2021. DOI: 10.33919/ansd.19.1.5. Disponível em: https://ojs.nbu.bg/index.php/ANSD/article/view/507. Acesso em: 26 apr. 2024.