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. 1–11, 2021. DOI: 10.12775/EQ.2021.024. Disponível em: https://apcz.umk.pl/EQ/article/view/EQ.2021.024. Acesso em: 7 dec. 2021.