KOYNOVA, T.; KOLEVA, V. Visitors’ opinions on the environmental protection in Shumen Plateau Nature Park from the negative anthropogenic impact of a nearby city, Bulgaria. Ecological Questions, [S. l.], v. 32, n. 3, p. 59–65, 2021. DOI: 10.12775/EQ.2021.024. Disponível em: https://apcz.umk.pl/EQ/article/view/34430. Acesso em: 25 apr. 2024.