N. Koeppen, K. Polkehn, and H. Wandke. Measuring Behavior 2002, 4th International Cofnerence on
Methods and Techniques in Behavioral Research, 27-30 August 2002, Amsterdam, (2002)
S. Simoff. Proceedings of the MDKM/KDD2000 Workshop on
Multimedia Data Mining, page 104--109. www.cs.ualberta.ca/~zaiane/mdm\_kdd2000/mdm00-15.pdf, (2000)
A. Halevy, and J. Madhavan. IJCAI-03, Proceedings of the Eighteenth International Joint Conference
on Artificial Intelligence, Acapulco, Mexico, August 9-15, 2003, page 1567-1572. Morgan Kaufmann, (2003)