Lertkultanon, Yaowaporn, Maneewan Chatawanich, Somphob Chatawanich, and Korakot Montreesuksirikul. “The 9As Strategy for Sustainable Management of Man-Made Attractions: a Case Study of Ba Na Hills, Vietnam”. Dusit Thani College Journal 17, no. 2 (August 30, 2023): 181–194. accessed May 16, 2025. https://so01.tci-thaijo.org/index.php/journaldtc/article/view/269368.