R. Jäschke, F. Eisterlehner, A. Hotho, und G. Stumme. RecSys '09: Proceedings of the 2009 ACM Conference on Recommender Systems, New York, NY, USA, ACM, (2009)(to appear).
S. McNee, N. Kapoor, und J. Konstan. Proceedings of the 2006 20th anniversary conference on Computer supported cooperative work, Seite 171--180. New York, NY, USA, ACM, (2006)