Smith, Michael K.; Chris Welty, Deborah L. McGuinness. OWL Ontology Web Language Guide. W3C. 2004-02-10 [2008-07-15]. (原始内容存档于2006-01-18).引文使用过时参数coauthors (帮助)
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Smith, Michael K.; Chris Welty, Deborah L. McGuinness. OWL Ontology Web Language Guide. W3C. 2004-02-10 [2008-07-15]. (原始内容存档于2006-01-18).引文使用过时参数coauthors (帮助)