U.S.Government Printing Office1938-Agriculture handbook / United States Department of Agriculture
no.3, 15 , Miscellaneous publication / United States Department of Agriculture
no.299
by Soil Survey Staff, Bureau of Plant Industry, Soils, and Agricultural Engineering
Agricultural Research Administration, U.S. Dept. of Agriculture : For sale by the Supt. of Docs., U.S. G.P.O.[1951][Rev. ed.]Agriculture handbook / United States Department of Agriculture
no. 18