Sangsuk, P. ., O. . Charoensuk, and C. . Kleebbua. “A Causal Model of Learning Achievement of Upper Primary Students With Learning Engagement As a Mediator Variable”. Kasetsart Journal of Social Sciences, vol. 43, no. 2, Apr. 2022, p. 337‒344, https://so04.tci-thaijo.org/index.php/kjss/article/view/258546.