I. Cvijikj, and F. Michahelles. Proceedings of the 15th International Academic MindTrek Conference: Envisioning Future Media Environments, page 175--182. New York, NY, USA, ACM, (2011)
D. Millen, and M. Fontaine. GROUP '03: Proceedings of the 2003 international ACM SIGGROUP conference on Supporting group work, page 205--211. New York, NY, USA, ACM, (2003)
A. Blanchard, and M. Markus. Communities and Technologies 2007: Proceedings of the Third Communities and Technologies Conference, page 323-350. London, Springer, (2007)
K. Winkler, and H. Mandl. 27. Ludwig-Maximilians-Universität München, Institut für Pädagogische Psychologie und Empirische Pädagogik, Lehrstuhl Prof. Dr. Heinz Mandl, (2003)