G. Mineau, G. Stumme, and R. Wille. Conceptual Structures: Standards and Practices. Proc. ICCS '99, volume 1640 of LNAI, page 423-441. Heidelberg, Springer, (1999)
G. Stumme, and K. Wolff. Advances in Database Technologies. Proc. Intl. Workshop on Data Warehousing and, volume 1552 of LNCS, page 117-128. Heidelberg, Springer, (1999)
M. Skorsky, G. Stumme, R. Wille, and U. Wille. Proc. Workshop on Knowledge Management, Organizational Memory and Reuse, 5th German Conf. on, Würzburg, (March 1999)
S. Prediger, and G. Stumme. Proc. 6th Intl. Workshop Knowledge Representation Meets Databases (KRDB'99), CEUR Workshop Proc. 21, (1999)Also in: P. Lambrix et al (Eds.): Proc. Intl. Workshop on Description Logics (DL'99). CEUR Workshop Proc. 22, 1999
http://ceur-ws.org/Vol-21.