1. Incorporated Merriam-Webster, WWWebster Dictionary, http://www.mw.com/dictionary, 1999.
2. N. Guarino, Formal ontology and information systems, in: Proceedings of the First International Conference on FOIS, Trento, Italy, 6–8 June 1998.
3. Mike Uschold, Robert Jasper, A framework for understanding and classifying ontology applications, in: V. Benjamins, B. Chasdrasekaran, A. Gomez-Perez, N. Guarino, M. Uschold (Eds.), Proceedings of the IJCAI-99 workshop on ontologies and Problem-Solving Methods (KRR5), Stockholm, Sweden, Vol. 18, August 2 1999, pp. 1–11. CEUR-WS.
4. Machine-negotiated, ontology-based EDI;Lehmann,1995
5. N. Guarino, Semantic matching: formal ontological distinctions for information organization, extraction, and integration, in: M.T. Pazienza (Ed.), Information Extraction: A Multidisciplinary Approach to an Emerging Information Technology, Vol. 1299, Springer, Berlin, 1997, pp. 139–170.