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3. T. Berners-Lee, R. Fielding, U.C. Irvine, L. Masinter: Uniform Resource Identifiers (URI): Generic Syntax. RFC 2396. IETF (1998).
4. Patrick Hayes (ed): RDF Model Theory. W3C Working Draft (2001) http://www.w3.org/TR/rdf-mt/
5. Art Barstow, Dave Beckett (eds): RDF Test Cases. W3C Working Draft (2001) http://www.w3.org/TR/rdf-testcases/