In: Andreas Dengel; K. Berns; Thomas Breuel; Frank Bomarius; Thomas Roth-Berghofer (Hrsg.). Proceedings of the 31st Annual German Conference on Artificial Intelligence. German Conference on Artificial Intelligence (KI-2008), 31st, September 23-26, Kaiserslautern, Germany, Pages 127-134, Lecture Notes in Artificial Intelligence (LNAI), No. 5243, ISBN 9783540858447, Springer, Heidelberg, 2008.