Cita APA (7a ed.)

Gehrs, J. H. (1937). Soils and crops. Macmillan.

Cita Chicago Style (17a ed.)

Gehrs, John H. Soils and Crops. New York: Macmillan, 1937.

Cita MLA (8a ed.)

Gehrs, John H. Soils and Crops. Macmillan, 1937.