D. R. Ramdania, D. S. Maylawati, Y. A. Gerhana, N. A. Suwastika, and M. A. Ramdhani "Octalysis Audit to Analyze gamification on Kahoot!", Advances in Science, Technology and Engineering Systems Journal, vol. 6, no. 1, pp. 457–463, 2021, doi: 10.25046/aj060149.