Khum-un, S., and S. . . Ruaengsri. “The Development of Mathematics Learning Activities Using a Constructivist Approach for Undergraduate Students in a Mathematics Education Program”. SOCIAL SCIENCES RESEARCH AND ACADEMIC JOURNAL, vol. 19, no. 2, May 2024, pp. 173-86, https://so05.tci-thaijo.org/index.php/JSSRA/article/view/270464.