United States. Department of Agriculture. (1927). Circular. U.S. Dept. of Agriculture : [for sale by the Supt. of Docs., U.S. G.P.O..
芝加哥风格引文United States. Department of Agriculture. Circular. [Washington]: U.S. Dept. of Agriculture : [for sale by the Supt. of Docs., U.S. G.P.O., 1927.
MLA引文United States. Department of Agriculture. Circular. U.S. Dept. of Agriculture : [for sale by the Supt. of Docs., U.S. G.P.O., 1927.
警告：这些引文格式不一定是100％准确.