Trayangkul, Varaporn, Prapawan Trakulkasemsuk, and Supawadee Wongsakul. 2022. “The School Administrators’ Competencies Affecting Academic Administration in School Teachers’ Opinions Under The Office of Secondary Educational Service area 3”. Saengtham College Journal 14 (2). Nakhon Phathom, Thailand:279-99. https://so01.tci-thaijo.org/index.php/scj/article/view/264091.