- Recommender Systems for the Social Web, volume 32 of Intelligent Systems Reference Library, Springer, Berlin/Heidelberg, (2012)
- Recommender Systems Handbook, Springer, New York, (2011)
- Knowledge Processing and Data Analysis, volume 6581 of Lecture Notes in Computer Science, page 136--149. Berlin/Heidelberg, Springer, (2011)
- AI Communications 21(4):231-247 (2008)
- Workshop on Knowledge Discovery, Data Mining, and Machine Learning, page 44 --51. (September 2009)
- Workshop Proceedings of Lernen - Wissensentdeckung - Adaptivität LWA 2007, page 13-20. Martin-Luther-Universität Halle-Wittenberg, (September 2007)
- Proc. of the 4th International Semantic Web Conference, (2005)
- IJCAI, page 2772-2777. (2007)
- CSCW '06: Proceedings of the 2006 20th anniversary conference on Computer supported cooperative work, page 171--180. New York, NY, USA, ACM Press, (2006)
- Commun. ACM 40(3):63--65 (1997)


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