R. Jäschke, A. Hotho, C. Schmitz, and G. Stumme. Proc. 18. Workshop Grundlagen von Datenbanken, page 80-84. Halle-Wittenberg, Martin-Luther-Universität, (June 2006)
M. Rosen-Zvi, T. Griffiths, M. Steyvers, and P. Smyth. Proceedings of the 20th conference on Uncertainty in artificial intelligence, page 487--494. Arlington, VA, USA, AUAI Press, (2004)
S. Decker, and M. Frank. Proc.\ WWW Workshop on Application Design, Development and Implementation Issues in the Semantic Web, Net York City, NY, (May 2004)
P. Mika. Proceedings of the 4th International Semantic Web Conference, volume 3729 of Lecture Notes in Computer Science, page 522-536. Springer, (2005)
P. Cobb, and H. Bauersfeld. The Emergence of Mathermatical Meaning: Interactions in Classroom Cultures, Lawrence Erlbaum Associates, Hillside, NJ, (1995)
I. Mohomed, A. Chin, J. Cai, and E. d. de Lara. 6th IEEE Workshop on Mobile Computing Systems and Applications (WMCSA), English Lake District, UK, (2004)