United States. Dept. of Agriculture. Economic Research Service, United States. Dept. of Agriculture. Economics and Statistics Service, & United States. World Food and Agricultural Outlook and Situation Board. (1981). Wheat outlook & situation. The Service.
芝加哥风格引文United States. Dept. of Agriculture. Economic Research Service, United States. Dept. of Agriculture. Economics and Statistics Service, 与 United States. World Food and Agricultural Outlook and Situation Board. Wheat Outlook & Situation. [Washington, D.C.]: The Service, 1981.
MLA引文United States. Dept. of Agriculture. Economic Research Service, et al. Wheat Outlook & Situation. The Service, 1981.
警告：这些引文格式不一定是100％准确.