M. Noll, C. man Au Yeung, N. Gibbins, C. Meinel, and N. Shadbolt. SIGIR '09: Proceedings of the 32nd international ACM SIGIR conference on Research and development in information retrieval, page 612--619. New York, NY, USA, ACM, (2009)
A. Shepitsen, J. Gemmell, B. Mobasher, and R. Burke. RecSys '08: Proceedings of the 2008 ACM conference on Recommender systems, page 259--266. New York, NY, USA, ACM, (2008)