P. Yannarut, W. Kasemsukpipat, and T. Somchaipeng, “A Study of Mathematical Concept of Mathayomsuksa 3 Students by Using a Concept Attainment Model”, Humanities and Social Sciences Journal of Pibulsongkram Rajabhat University, vol. 16, no. 2, pp. 726–738, Sep. 2022.