Zhu, Tingshao, Bin Hu, Jingzhi Yan, and Xiaowei Li. “Semi-Supervised Learning for Personalized Web Recommender System”. Computing and Informatics 29, no. 4 (January 26, 2012): 617–627. Accessed April 30, 2025. https://www.cai.sk/ojs/index.php/cai/article/view/104.