Seeda, Tantawan, and Parichart Prasertsang. “The Development of Mathematical Problem Solving Ability Through Open Approach for Grade 10 Students”. Journal of Roi Et Rajabhat University 15, no. 2 (August 30, 2021): 79–90. Accessed April 29, 2024. https://so03.tci-thaijo.org/index.php/reru/article/view/239913.