Hombuppha, A. . ., and K. . Phumpuang. “The Development of E-Learning Courseware With Problem-Based Learning on The Subject of Computer Programming for High Vocational Certificate Students”. Liberal Arts Review, vol. 15, no. 2, Dec. 2020, pp. 76-90, https://so04.tci-thaijo.org/index.php/larhcu/article/view/242815.