2020-04-20T07：21：12Z http://oaipmh.hindawi.com/oai-pmh/oai.aspx oai_dc http://www.openarchives.org/OAI/2.0/oai_dc.xsd http://www.openarchives.org/OAI/2.0/oai_dc/ oai_dc_agris http://www.fao.org/agris/agmes/dtd/dlio.dtd http://www.fao.org/agris/agmes/dtd/ MARC21 http://www.loc.gov/standards/marcxml/schema/MARC21slim.xsd http://www.loc.gov/MARC21/slim