R. Jäschke, A. Hotho, C. Schmitz, and G. Stumme. Proceedings of the 15th International Conference on Conceptual Structures (ICCS 2007), volume 4604 of Lecture Notes in Artificial Intelligence, page 283--295. Berlin/Heidelberg, Springer-Verlag, (July 2007)
A. Hotho, R. Jäschke, C. Schmitz, and G. Stumme. The Semantic Web: Research and Applications, volume 4011 of Lecture Notes in Computer Science, page 411--426. Berlin/Heidelberg, Springer, (June 2006)
J. Tane, C. Schmitz, G. Stumme, S. Staab, and R. Studer. Mobiles Lernen und Forschen - Beiträge der Fachtagung an der Universität, page 93-104. Kassel University Press, (November 2003)