Chumpoojan, Sukrit, and Montri Thongmoon. 2021. “The Development of Mathematical Problem-Solving Ability by Using Deductive Learning With GeoGebra Program on Preliminary Data Analysis Topic for Matthayomsuksa 6 Students”. Journal of Roi Et Rajabhat University 15 (3):125-33. https://so03.tci-thaijo.org/index.php/reru/article/view/242683.