Phusaisom S, Cojorn K. A DEVELOPMENT OF LEARNING ACTIVITY BASED ON PROBLEM BASED LEARNING COOPERATED WITH COLLABORATIVE LEARNING APPROACH FOR PROMOTING PROBLEM SOLVING COMPETENCY OF MATTHAYOMSUKSA 4 STUDENTS. JMND [internet]. 2020 Sep. 21 [cited 2026 Oct. 4];7(9):265-82. available from: https://so03.tci-thaijo.org/index.php/JMND/article/view/246741