Liu, Feng-Jung, and Chia-Mei Lu. “Design and Implementation of A Collaborative Educational Gamification Authoring System”. International Journal of Emerging Technologies in Learning (iJET) 16, no. 17 (September 6, 2021): pp. 277–289. Accessed March 29, 2024. https://online-journals.org/index.php/i-jet/article/view/24087.