1. Abiteboul, S., Buneman, P., Suciu, D.: Data on the Web: From Relations to Semistructured Data and XML. Morgan Kaufmann Series in Data Management Systems (1999)
2. Baeza-Yates, R., Ribeiro-Neto, B.: Modern Information Retrieval. ACM Press, Addison-Wesley (1999)
3. Bidault, A., Froidevaux, C., Safar, B.: Repairing Queries in a Mediator Approach. In: Proceedings of the ECAI 2002, Lyon, France (2002)
4. Dongwon, L.: Query Relaxation for XML Model. PhD thesis, University of California (2002)
5. Donini, F.M., Lenzerini, M., Nardi, D., Schaerf, A.: Reasoning in Description Logics. In: Brewka, G. (ed.) Principles of Knowledge Representation, ch. 1, pp. 191–236. CSLI Publications (1996)