Silik, Cemal, Yusuf Dündar, e Ertuğrul Düzgün. «Environmental Performance of Accommodation Establishments in the Protected Areas: Case of Bolu, Turke»y. Revista Turismo & Desenvolvimento 41 (Maio 25, 2023): 21-39. Acedido Maio 3, 2024. https://proa.ua.pt/index.php/rtd/article/view/30495.