Cultural ecosystem services provided by natural heritage sites in karst territories of Smolyan region, Bulgaria. Research Announcements "Heritage BG", [S. l.], n. 1, p. 65–81, 2025. DOI: 10.58894/AR-HBg.2021.1.65-81. Disponível em: https://periodicals.uni-sofia.bg/index.php/AR-NBg/article/view/1393. Acesso em: 10 mar. 2026.