McNicol, Barbara. «The Sustainability of Commercial Tour Operations in Protected Natural Areas: Defining Categories of Environmental Supply». Anais Brasileiros de Estudos Turísticos 6, no. 1 (abril 15, 2016): 20–27. Accedido julio 18, 2024. https://periodicos.ufjf.br/index.php/abet/article/view/3114.