S. Rendle, L. Marinho, A. Nanopoulos, and L. Schmidt-Thieme. KDD '09: Proceedings of the 15th ACM SIGKDD international conference on Knowledge discovery and data mining, page 727--736. New York, NY, USA, ACM, (2009)
P. Symeonidis, A. Nanopoulos, and Y. Manolopoulos. RecSys '08: Proceedings of the 2008 ACM conference on Recommender systems, page 43--50. New York, NY, USA, ACM, (2008)