Pharino, C., and S. Leawpenwong. “Investigating Gaps in Sustainable Community Tourism: A Case Study of Local Communities in the Vicinity of Khon Kaen Zoo”. Journal of Mekong Societies, vol. 11, no. 2, Aug. 2015, pp. 61-74, https://so03.tci-thaijo.org/index.php/mekongjournal/article/view/38745.