CONCEPTShttp://cat.aii.caas.cn/concept/30661cat.aii.caas.cnhttp://stitch.cs.vu.nl/vocabularies/rameau/ark:/12148/cb119308747stitch.cs.vu.nlhttp://www.eionet.europa.eu/gemet/concept/367www.eionet.europa.euhttp://www.fao.org/countryprofiles/geoinfo/geopolitical/resource/Americaswww.fao.org。