APA
(1938). Soils & men, yearbook of agriculture 1938. Washington, D.C: U.S. Government Printing Office.
Chicago
1938. Soils & men, yearbook of agriculture 1938. Washington, D.C: U.S. Government Printing Office.
Harvard
(1938). Soils & men, yearbook of agriculture 1938. Washington, D.C: U.S. Government Printing Office.
MLA
Soils & men, yearbook of agriculture 1938. Washington, D.C: U.S. Government Printing Office. 1938.
