Jomtraikhup , Ratchaphon, Sikarn Peantanyakorn, and Sawat Phothiwat. “A Casual Relationship Model of Selected Factors Affecting Effectiveness of Secondary Schools in the Northeastern Part of Thailand”. Journal of Roi Et Rajabhat University 15, no. 1 (December 16, 2020): 16-27. Accessed June 13, 2021. https://so03.tci-thaijo.org/index.php/reru/article/view/238505.