1. Akkermans, J. M., Borst, P., Pos, A., & Top, J. (1995). Experiences in conceptual modelling for a mechatronic design library. In Gaines, B. & Musen, M., editors, Proceedings of the ninth international knowledge acquisition workshop KAW'95, pages volume 2, pages 39.1–39.15. University of Calgary, SRDG Publications.
2. Benjamin, J. (1995). Towards generic ontologies.
3. Borst, P., Akkermans, H., Pos, A., & Top, J. (1995). The physsys ontology for physical systems. In Working papers of the ninth international workshop on qualitative reasoning, pages 11–21. Department of Social Science Informatics (SWI), University of Amsterdam.
4. Gruber, T. R. (1993). A translation approach to portable ontology specifications. Knowledge Acquisition, 5:199–220.
5. Guarino, N., Carrara, M., & Giaretta, P. (1994). An ontology of meta-level categories. In Doyle, J., Sandewall, E., & Torasso, P., editors, Principles of knowledge representation and reasoning: proceedings of the fourth international conference (KR94), San Mateo, California. Morgan Kaufmann.