Poonchu, Pongsa, and Sajeewan Darbavasu. 2021. “Characteristics of Professional Administrators Affecting the Efficiency of Private School Management under the Samut Prakan Provincial Education Office”. Journal of Humanities and Social Sciences, Rajapruk University 7 (2):156-69. https://so03.tci-thaijo.org/index.php/rpu/article/view/254783.