APA-referens (7:e uppl.)

Singh,Soubam Prenchandra. (2018). Eco.tourism environmental problems & sustainable development. Discovery publishing House.

Chicago-referens (17:e uppl.)

Singh,Soubam Prenchandra. Eco.tourism Environmental Problems & Sustainable Development. New Delhi: Discovery publishing House, 2018.

MLA-referens (9:e uppl.)

Singh,Soubam Prenchandra. Eco.tourism Environmental Problems & Sustainable Development. Discovery publishing House, 2018.

Varning: dessa hänvisningar är inte alltid fullständigt riktiga.