Chaiprasert C, Malaithao T. Development of Problem-Based Learning Skill Exercises in the Civics Course Based on the Four Iddhipāda Principles for Grade 8 Students at Wat Weluwan Witthaya School, Bueng Kan Province. JBER [internet]. 2026 Sep. 21 [cited 2026 Sep. 28];12(3):885-96. available from: https://so06.tci-thaijo.org/index.php/jber/article/view/295413