Conceptual Structures: Theory, Tools and Applications 6th International Conference on Conceptual Structures, ICCS'98, Montpellier, France, August, 10-12, 1998, Proceedings - Mugnier, Marie-Laure; Mugnier, Marie-Laure; Chein, Michel; Chein, Michel (Springer Berlin Heidelberg : Imprint: Springer, 1998)