Koompapun, P., and J. Ketsing. “The Development of 10th Graders’ Collaborative Problem Solving Competency Using DEEPER Scaffolding Model”. STOU Education Journal, vol. 17, no. 1, June 2024, pp. 16-36, https://so05.tci-thaijo.org/index.php/edjour_stou/article/view/266771.