K. Tso-Sutter, L. Marinho, and L. Schmidt-Thieme. SAC '08: Proceedings of the 2008 ACM symposium on Applied computing, page 1995--1999. New York, NY, USA, ACM, (2008)
D. Parra, and P. Brusilovsky. Proceedings of the Workshop on Web 3.0: Merging Semantic Web and Social Web, volume 467 of CEUR Workshop Proceedings, (June 2009)
S. Doerfel, R. Jäschke, A. Hotho, and G. Stumme. Proceedings of the 4th ACM RecSys workshop on Recommender systems and the social web, page 9--16. New York, NY, USA, ACM, (2012)
R. Jäschke, L. Marinho, A. Hotho, L. Schmidt-Thieme, and G. Stumme. Workshop Proceedings of Lernen - Wissensentdeckung - Adaptivität (LWA 2007), page 13-20. Martin-Luther-Universität Halle-Wittenberg, (September 2007)