Doungphumek, N., K. Wiwanthamongkon, and N. Punkong. “The Development of Training Kits to Enhance Learning Outcomes and Mathematical Problem - Solving Skills According to the Vygotsky and Feuerstein Theoretical Frameworks for Mathayom Suksa 3 Students”. STOU Education Journal, vol. 19, no. 1, June 2026, pp. 19-34, https://so05.tci-thaijo.org/index.php/edjour_stou/article/view/288014.