1. Baader, F., et al. (eds.): The Description Logic Handbook: Theory, Implementation and Applications. Cambridge University Press, Cambridge (2007)
2. Bray, T., et al.: Extensible markup language (xml) 1.0, 5th edn. W3C Recommendation, November 26 (2008),
http://www.w3.org/TR/REC-xml/
3. Carle, E.: The Very Hungry Caterpillar. Philomel Books (1969)
4. Date, C.J., Darwen, H.: ISO/IEC 9075-2:2008 (SQL - Part 2: Foundations), The SQL Standard, 3rd edn. Addison-Wesley Publishing Company, Reading (1993)
5. Katsuno, H., Mendelzon, A.O.: On the difference between updating a knowledge base and revising it. In: Gärdenfors, P. (ed.) Belief Revision, pp. 183–203. Cambridge University Press, Cambridge (1992)