1. Patel-Schneider, P., Hayes, P., Horrocks, I.: Web ontology language (OWL) abstract syntax and semantics (2004),
http://www.w3.org/TR/owl-semantics/
2. van der Sluijs, K., Houben, G.J.: Relating user tags to ontological information. In: Proceedings of the 5th International Workshop on Ubiquitous User Modeling (UbiqUM 2008), Workshop at the 2008 International Conference on Intelligent User Interfaces (IUI 2008) (2008)
3. Milea, V., Frasincar, F., Kaymak, U.: Knowledge engineering in a temporal semantic web context. In: The Eighth International Conference on Web Engineering (ICWE 2008). IEEE Computer Society Press, Los Alamitos (2008)
4. Roddick, J.F., Patrick, J.D.: Temporal semantics in information systems - a survey. Information Systems 17(3), 249–267 (1992)
5. Pugliese, A., Udrea, O., Subrahmanian, V.S.: Scaling RDF with time. In: WWW 2008: Proceeding of the 17th international conference on World Wide Web, pp. 605–614. ACM, New York (2008)