"A second property with the same name as this property has been declared in the dcterms: namespace (http://purl.org/dc/terms/). See the Introduction to the document \"DCMI Metadata Terms\" (http://dublincore.org/documents/dcmi-terms/) for an explanation."@en-us . "An unambiguous reference to the resource within a given context."@en-us . . "1999-07-02" . "Identifier"@en-us . . "Recommended best practice is to identify the resource by means of a string conforming to a formal identification system. "@en-us . . "2008-01-14" . .