Singklieng, Sirikhwan, Sowwanee Sikkhabandit, and Khwanying Sriprasertpap. “Academic Management Strategies of English Program School Under Office of the Private Education Commission (OPEC): Bangkok District”. Rajapark Journal 16, no. 45 (April 14, 2022): 549–569. Accessed May 8, 2024. https://so05.tci-thaijo.org/index.php/RJPJ/article/view/257279.