Thanakoolkaweepong T, Kongthip Y, Hajisalah S, Janjaroon A. The Development of Instructional Geometry Problems Activities to Enhance Critical Problem Solving by Design Thinking Process for Secondary Students. J.Humanities Social Sciences [internet]. 2023 Apr. 19 [cited 2026 Oct. 4];6(2):811-30. available from: https://so04.tci-thaijo.org/index.php/jmhs1_s/article/view/263181