Sangthong, S., and M. Wongsaphan. “DEVELOPMENT OF PROBLEM – SOLVING ABILITY IN MATHEMATICAL FOR MATHAYOMSUKSA 4, USING INQUIRY BASED LEARNING AND COOPERATIVE PROBLEM SOLVING LEARNING PACKAGE PROBABILITY”. Journal of MCU Nakhondhat, vol. 7, no. 9, Sept. 2020, pp. 221-35, https://so03.tci-thaijo.org/index.php/JMND/article/view/246738.