1. F. Baader. “Terminological Cycles in kl-one-based Knowledge Representation Languages.” In Proceedings of the 8th National Conference of the AAAI, pp. 621–626, Boston, Mas., 1990.
2. F. Baader. “A Formal Definition for the Expressive Power of Knowledge Representation Languages.” In Proceedings of the 9th European Conference on Artificial Intelligence, pp. 53–58, Stockholm, Sweden, 1990.
3. F. Baader. “Augmenting Concept Languages by Transitive Closure of Roles: An Alternative to Terminological Cycles.” To appear in Proceedings of IJCAI '91.
4. F. Baader, H.-J. Bürckert, J. Heinsohn, B. Hollunder, J. Müller, B. Nebel, W. Nutt, H.-J. Profitlich. Terminological Knowledge Representation: A Proposal for a Terminological Logic DFKI Technical Memo TM-90-04, DFKI, Postfach 2080, D-6750 Kaiserslautern, Germany.
5. F. Baader, H.-J. Bürckert, B. Hollunder, W. Nutt, J. H. Siekmann. “Concept Logics” In Proceedings of the Symposium on Computational Logics, Brüssel, November 1990.