1. Ontology Summit 2007 – Ontology, Taxonomy, Folksonomy: Understanding the Distinctions;Gruninger;Applied Ontology,2008
2. Semantic Web Road Map;Berners-Lee,1998
3. Semantic Representation of Contract Knowledge Using Multi Tier Ontology;Kabilan,2003
4. Extending UML to Support Ontology Engineering for the Semantic Web;Baclawski,2001
5. Towards a Precise Semantics for Object-oriented Modeling Techniques;Breu,1997