Phương, Nguyễn Duy, and Từ Minh Phương. “A Collaborative Filtering Algorithm for Sparse Data”. <i>Journal of Computer Science and Cybernetics</i> 24, no. 1 (July 10, 2012): 62–74. Accessed November 4, 2025. https://jcc.vast.vn/jcc/article/view/1229.