P. Schonhofen. WI '06: Proceedings of the 2006 IEEE/WIC/ACM International Conference on Web Intelligence, page 456--462. Washington, DC, USA, IEEE Computer Society, (2006)
X. Hu, N. Sun, C. Zhang, and T. Chua. CIKM '09: Proceeding of the 18th ACM conference on Information and knowledge management, page 919--928. New York, NY, USA, ACM, (2009)
E. Gabrilovich, and S. Markovitch. IJCAI'07: Proceedings of the 20th international joint conference on Artifical intelligence, page 1606--1611. San Francisco, CA, USA, Morgan Kaufmann Publishers Inc., (2007)
S. Banerjee, K. Ramanathan, and A. Gupta. SIGIR '07: Proceedings of the 30th annual international ACM SIGIR conference on Research and development in information retrieval, page 787--788. New York, NY, USA, ACM, (2007)