(Hengsawang), Phra Direk Kittinago, Vitthaya Thongdee, and Somkhuan Namseethan. “The Development of a Learning Activity Package on the Analysis of Key Issues in Thai History Using Problem-Based Learning (PBL) for Matthayom Suksa 4 Students at Wat Sriwichai Wanaram School, Loei Province”. Journal of Graduate MCU KhonKaen Campus 13, no. 2 (June 23, 2026): 82–96. accessed October 14, 2026. https://so02.tci-thaijo.org/index.php/jg-mcukk/article/view/278728.