Rozahi Istambul, Muhammad, and Egi Abinowi. “Reliability Measurement of Learning Outcome Using K-Means Cluster Technique”. International Journal of Psychosocial Rehabilitation 24, no. 2 (April 30, 2020): 8318–8322. Accessed June 16, 2025. https://www.psychosocial.com/index.php/ijpr/article/view/2759.