1. Staab S, Studer R (2004) Handbook on Ontologies. Springer, Heidelberg.
2. Stracia U (1998) A Fuzzy Description Logic. In: AAAI’ 98/IAAI’ 98: Proceedings of the Fifteenth National/tenth Conference on Artificial Intelligence/ Innovative Applications of Artificial Intelligence, pp 594–599.
3. Straccia U (2005) Towards a Fuzzy Description Logic for the Semantic Web. In: Proceedings of the Second European Semantic Web Conference, pp 167–181.
4. Stoilos G, Stamou G, Tzouvaras V et al (2005) The Fuzzy Description Logic f-SHIN. In: Proceedings of the International Workshop on Uncertainty Reasoning for the Semantic Web.
5. Murphy GL (2002) The Big Book of Concepts. MIT Press, Boston.