Srijandee, T. . “THE DEVELOPMENT OF MATHEMATICS LEARNING ACTIVITIES ON LINEAR EQUATION BASED ON CONSTRUCTIVIST THEORY SUPPLEMENTED BY POYA’S PROBLEM SOLVING PRACTICE FOR MATHAYOMSUKSA 1 STUDENTS”. Journal of MCU Nakhondhat, vol. 9, no. 9, Sept. 2022, pp. 328-3, https://so03.tci-thaijo.org/index.php/JMND/article/view/263910.