APA

United States Departament of Agriculture U., . (1951). Yearbook of agriculture 1957 : soil. Washington: United States Government Printing Office.

Chicago

United States Departament of Agriculture Usda, . 1951. Yearbook of agriculture 1957 : soil. Washington: United States Government Printing Office.

Harvard

United States Departament of Agriculture U., . (1951). Yearbook of agriculture 1957 : soil. Washington: United States Government Printing Office.

MLA

United States Departament of Agriculture Usda, . Yearbook of agriculture 1957 : soil. Washington: United States Government Printing Office. 1951.