Phungsuk R, Viriyavejakul C, Ratanaolarn T. Development of a problem-based learning model via a virtual learning environment. kasetsart J. Soc. Sci. [internet]. 2017 Mar. 1 [cited 2026 Sep. 17];38(3):297-306. available from: https://so04.tci-thaijo.org/index.php/kjss/article/view/242738