1. Convention on Biological Diversity. Article 2. Use of Termshttps://www.cbd.int/convention/articles/?a=cbd-02
2. Definition Paradoxes: From concept to definition;Björk,2007
3. Ecotourism: Competing and conflicting schools of thought;Higham,2007
4. Tourism, Ecotourism and Protected Areas: The State of Nature-Based Tourism around the World and Guidelines for Its Development;Ceballos-Lascurain,1996
5. The International Ecotourism Societyhttps://ecotourism.org/what-is-ecotourism