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)
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.