1. Towards principles for the design of ontologies used for knowledge sharing;Gruber,1993
2. Learning Technology Standards Comittee of the IEEE, Draft Standard for Learning Objects Metadata, IEEE Draft P1484.12.1/D6.412, 2002, .
3. L. Aroyo, S. Pokraev, R. Brussee, Preparing SCORM for the semantic Web, in: Proceedings of International Conference on Ontologies, Databases, and Applications of Semantics, Catania, Italy, 2003.
4. R. Mizogushi, Ontology-based systematization of functional knowledge, in: Proceedings of tools and methods of competitive engineering (TMCE2002), Wuhan, China, 2002.
5. B. Simon, Do e-Learning standards meet their challenges? in: Proceedings of Workshops Standardisierung im e-Learning, Frankfurt, Deutschland, 2002.