World Wide Web Consortium (W3C) (2004). OWL Web Onthology Language guide. W3C Recommendation 10 Feb. 2004, 2004. http://www.w3.org/TR/owl-guide...
World Wide Web Consortium (W3C). (2008a). SKOS Simple Knowledge Organization System Primer. W3C Working Draft 29 August 2008, 2008. http://www.w3.org/TR/2008/WD-skos-primer-20080829/...
World Wide Web Consortium (W3C). (2008b). SKOS Simple Knowledge Organization System Reference. W3C Working Draft 29 August 2008, 2008. http://www.w3.org/TR/2008/WD-skos-reference-20080829/....
World Wide Web Consortium (W3C). (2008c). SPARQL Query Language for RDF. W3C Recommendation 15 January 2008, 2008. http://www.w3.org/TR/owl-guide...