X. Liu, Y. Yu, C. Guo, and Y. Sun. Proceedings of the 23rd ACM International Conference on Conference on Information and Knowledge Management, page 121--130. New York, NY, USA, ACM, (2014)
J. Zhu, M. Ma, J. Guo, and Z. Wang. INTERNATIONAL JOURNAL OF PATTERN RECOGNITION AND ARTIFICIAL INTELLIGENCE, 21 (2):
375-395(March 2007)International Workshop on Web Personalization, Recommender Systems and
Intelligent User Interfaces, Reading, ENGLAND, OCT, 2005.