C. Basu, H. Hirsh, and W. Cohen. AAAI '98/IAAI '98: Proceedings of the fifteenth national/tenth conference on Artificial intelligence/Innovative applications of artificial intelligence, page 714--720. Menlo Park, CA, USA, American Association for Artificial Intelligence, (1998)
D. Billsus, and M. Pazzani. ICML '98: Proceedings of the Fifteenth International Conference on Machine Learning, page 46--54. San Francisco, CA, USA, Morgan Kaufmann Publishers Inc., (1998)
T. Bogers, and A. van den Bosch. RecSys '08: Proceedings of the 2008 ACM conference on Recommender systems, page 287--290. New York, NY, USA, ACM, (2008)