2000-10-01T19:20:30-04:00 http://an.oa.org/OAI-script?verb=ListMetadataFormats& identifier=oai:arXiv:hep-th/9901001 oai_rfc1807 http://www.openarchives.org/OAI/rfc1807.xsd oai_dc http://www.openarchives.org/OAI/dc.xsd http://purl.org/dc/elements/1.1