Chokri Ben Necib Johann Christoph Freytag Ontology Based Query Processing in Database Management Systems. 839-857 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2888&spage=839 2003 conf/coopis/2003 CoopIS/DOA/ODBASE db/conf/coopis/coopis2003.html#NecibF03