Zhu, Jianke, Hao Ma, Chun Chen, and Jiajun Bu. “Social Recommendation Using Low-Rank Semidefinite Program”. Proceedings of the AAAI Conference on Artificial Intelligence 25, no. 1 (August 4, 2011): 158–163. Accessed May 7, 2026. https://ojs.aaai.org/index.php/AAAI/article/view/7837.