J. Delgado, I. Gallego, S. Llorente, and R. García, IPROnto: An Ontology for Digital Rights Managemen t, Amsterda m, pp.111-120, 2003.

M. Dulong-de-rosnay, « Cognitive interfaces for legal expressions description - Application to copyrighted works, Online sharing and Transactions, Amsterda m, pp.121-130, 2003.

R. Gil, R. García, and J. Delgado, An interoperable framework for Intellectual Property Rights using web ontologies, LOAIT Workshop 2005 -Legal Ontologies and Artificial Intelligence Techniques, 2005.

D. Mulligan and A. Burstein, Implemen ting Copyright Limitations in Rights Expression Languages, ACM Workshop on Digital Rights Management, 2002.

I. and I. Fdis, MPEG-21 Rights Expression Language (REL, ISO/IEC JTC 1, pp.21000-21005, 2003.