P. Spyns, D. Oberle, R. Volz, J. Zheng, M. Jarrar, Y. Sure, R. Studer, and R. Meersman. Practical Aspects of Knowledge Management, 4th International Conference, PAKM 2002, Vienna, Austria, December 2-3, 2002, Proceedings, volume 2569 of Lecture Notes in Computer Science, page 189-200. Springer, (2002)
Y. Sure, S. Bloehdorn, P. Haase, J. Hartmann, and D. Oberle. Proceedings of the 12th Portuguese Conference on Artificial Intelligence - Progress in Artificial Intelligence (EPIA 2005), volume 3803 of LNCS, page 218 - 231. Covilha, Portugal, Springer, (December 2005)