APA

United States Departament of Agriculture U., . (1938). Yearbook of agriculture 1949 : trees. Washington: United States Government Printing Office.

Chicago

United States Departament of Agriculture Usda, . 1938. Yearbook of agriculture 1949 : trees. Washington: United States Government Printing Office.

Harvard

United States Departament of Agriculture U., . (1938). Yearbook of agriculture 1949 : trees. Washington: United States Government Printing Office.

MLA

United States Departament of Agriculture Usda, . Yearbook of agriculture 1949 : trees. Washington: United States Government Printing Office. 1938.