C. Wartena, R. Brussee, and M. Wibbels. Proceedings of the International Conference on Intelligent Sytem Design and Applications 2009 (ISDA 09), Pisa, Italy, (November 2009)
S. Rendle, and L. Schmidt-Thieme. Challenge of the 2009 ECML/PKDD at the European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases, ACM, (2009)