Soil erosion :
a critical problem in American agriculture.

APA Citation

United States. National Resources Board. Land Planning Committee., United States. Bureau of Agricultural Engineering., United States. Soil Conservation Service. (1935). Soil erosion: a critical problem in American agriculture. Washington [D.C.]: U.S. G.P.O..

MLA Citation

United States. National Resources Board. Land Planning Committee, United States. Bureau of Agricultural Engineering, and United States. Soil Conservation Service. Soil Erosion: a Critical Problem In American Agriculture. Washington [D.C.]: U.S. G.P.O., 1935.