1USCHOLD M. Knowledge Level Modelling: Concepts and Terminology[J]. The Knowledge Engineering Review, 1998, 13(1):5-29.
2CHANDRASEKARAN B, JOSEPHSON J R, BENJAMINS V R. What Are Ontologies, and Why Do We Need Them? [ER/OL]. http://www. informatik. unihamburg. de/W SV/teaching/proseminare/NavigationWebAr tikel/chandrasekaraneta199 . pdf, 2002-12-01.
3GRUBER T. Towards Principles for the Design of Ontologies Used for Knowledge Sharing [J]. International Journal of Human-Computer Studies, 1995, 43 (5/6):907-928.
4BUEHLER K, MCKEE L. The Open GIS Guide (Third Edition) [EB/OL]. Http://www.opengis.org,2002-09-08.
5BISHR Y A, PUNDT H, KUHN W, RDWAN M.Probing the Concepts of Information Communities-A First Step Toward Semantic Interoperability[A]. Goodchild M, Egenhofer M, Fegeas R, and Kottman. Interoperating Geographic Information Systems[C]. Kluwer:Norwell, 1999.
6WACHE H, VOGELE T, VISSER U, STUCKENSCHMIDT H, et al. Ontology-Based Integration of Information-A Survey of Existing Approaches[EB/OL].http://citeseer. nj. nec. com/wache01ontologybased.html, 2002-01-23.
7HORROCKS I. DAML + OIL-a Reasonable Ontology Language for the Semantic Web [EB/OL]. http://www. cs. man. ac. uk/- horrocks/Slides/aisb02col. pdf,2002-11-04.