In: J. Dix; L. Farinas del Cerro; U. Furbach (Hrsg.). Proceedings of Logics in Artificial Intelligence, European Workshop, JELIA '98. Logics in Artificial Intelligence, European Workshop (JELIA), Dagstuhl, Pages 169-183, LNAI 1489, Springer, 10/1998.
In: O. Herzog; A. Günter (Hrsg.). KI-98: Advances in Artificial Intelligence, 22nd Annual German Conference on Artificial Intelligence. German Conference on Artificial Intelligence (KI), Bremen, Springer Verlag, LNCS 1504, 1998.