Christopher, Leon, and Alexander Waworuntu. “Java Programming Language Learning Application Based on Octalysis Gamification Framework”. IJNMT (International Journal of New Media Technology) 8, no. 1 (June 27, 2021): 65-69. Accessed April 27, 2024. https://ejournals.umn.ac.id/index.php/IJNMT/article/view/2049.