Shahgerdi, A., Rezapouraghdam, H., Ghaedi, A., & Safshekan, S. (2016). The Tourism-Environment Nexus; Challenges and Opportunities. Journal of Sustainable Development Studies, 9(1), 17-33. https://www.airitilibrary.com/Article/Detail?DocID=P20151222007-201602-201607180030-201607180030-17-33
Bhattarai, A. (2004). Sustainable tourism [master's thesis, The University of Hong Kong]. Airiti Library. https://www.airitilibrary.com/Article/Detail?DocID=U0029-1812201200009816