Se, N., and M. . Wongsapan. “DEVELOPMENT OF MATHEMATICS LEARNING ACHIEVEMENT AND MATHEMATICAL CONNECTION ABILITY OF MATAYOMSUKSA 5 STUDENTS BY USING PROBLEM – BASED LEARNING MANAGEMENT”. Journal of MCU Nakhondhat, vol. 7, no. 8, Aug. 2020, pp. 104-19, https://so03.tci-thaijo.org/index.php/JMND/article/view/246264.