Singklieng สิริขวัญ, Sikkhabandit เสาวณีย์, and Sriprasertpap ขวัญหญิง. 2022. “Academic Management Strategies of English Program School Under Office of the Private Education Commission (OPEC): Bangkok District”. Rajapark Journal 16 (45). Bangkok, Thailand:549-69. https://so05.tci-thaijo.org/index.php/RJPJ/article/view/257279.