Stumme, G. and Wolff, K. E.. Numerical Aspects in the Data Model of Conceptual Information Systems. Advances in Database Technologies. Proc. Intl. Workshop on Data Warehousing and. editor(s) Kambayashi, Y. and Lee, Dik Kun and Lim, Ee-Peng and Mohania, M. K. and Masunaga, Y.. LNCS, (1552) 117-128, Springer, Heidelberg, Year 1999.

Stumme, Gerd. Acquiring Expert Knowledge for the Design of Conceptual Information Systems. Knowledge Acquisition, Modeling, and Management. Proc. 11th European. editor(s) Fensel, D. and Studer, R.. LNAI, (1621) 275-290, Springer, Heidelberg, Year 1999.

Stumme, Gerd. Dual Retrieval in Conceptual Information Systems. Datenbanksysteme in Büro, Technik und Wissenschaft. Proc. BTW'99. editor(s) Buchmann, A.. 328-342, Heidelberg, Year 1999.