營養政策和推廣中心(英语:Center for Nutrition Policyand Promotion)(Center for Nutrition Policyand Promotion;CNPP) 美国农业部食品安全次长(英语:Under Secretary of Agriculturefor Food Safety)
Center for International Food andAgriculturePolicy: 4. June 2006 [2013-09-16]. (原始内容存档 (PDF)于2013-10-21). Conrad, David E. Tenant Farming and Sharecropping