B. Müller, G. Viering, F. Ahlemann, and G. Riempp. Proceedings of the 15. European Conference on Information Systems (ECIS 2007), St. Gallen, Switzerland, (2007)
D. Beimborn, A. Maedche, and B. Mueller. Procedings of the 41. Annual Conference of the Gemran Gesellschaft für Informatik (Informatik 2011), Lectures Notes Informatics (LNI P-191), page 419-420. (2011)