A. Isaac, and R. Troncy. (EKAW'04) Workshop on Core Ontologies in Ontology Engineering, CEUR Proceedings Vol. 118, Whittlebury Hall, Northamptonshire, UK, (October 2004)
R. Garcia, and O. Celma. Proceedings of 4rd International Semantic Web Conference. Knowledge Markup and Semantic Annotation Workshop, Galway, Ireland, (2005)