Su, Chien-Yuan, Jiawei Chang, Tikai Chiu, and Tungcheng Hsieh. 2015. “A Cluster-Based Personalized Item Recommended Approach on the Educational Assessment System”. International Journal of Emerging Technologies in Learning (iJET) 10 (5):pp. 52-58. https://doi.org/10.3991/ijet.v10i5.4807.