CONCEPTShttp://cat.aii.caas.cn/concept/33872cat.aii.caas.cnhttp://eurovoc.europa.eu/909eurovoc.europa.euhttp://id.loc.gov/authorities/subjects/sh85045631id.loc.govhttp://lod.nal.usda.gov/nalt/5987lod.nal.usda.govhttp://stitch.cs.vu.nl/vocabularies/rameau/ark:/12148/cb11931301wstitch.cs.vu.nlhttp://www.eionet.europa.eu/gemet/concept/2992www.eionet.europa.euhttp://www.fao.org/countryprofiles/geoinfo/geopolitical/resource/Europewww.fao.orghttp://zbw.eu/stw/descriptor/16815-3zbw.eu。