Conceptual Structures: Standards and Practices 7th International Conference on Conceptual Structures, ICCS'99, Blacksburg, VA, USA, July 12-15, 1999, Proceedings - Tepfenhart, William M.; Tepfenhart, William M.; Cyre, Walling; Cyre, Walling (Springer Berlin Heidelberg : Imprint: Springer, 1999)