Khunsang, Yongyut. “The Development of Teaching by Using iTunes U Knowledge Base to Enhance the 21st Century Learners”. Ph.D. in Social Sciences Journal 8, no. S (October 31, 2018): 148–161. accessed August 30, 2026. https://so05.tci-thaijo.org/index.php/phdssj/article/view/102358.