APA (7th ed.) Citation

Gehrs, J. H. (1917). Productive agriculture: By John H. Gehrs. Macmillan.

Chicago Style (17th ed.) Citation

Gehrs, John Henry. Productive Agriculture: By John H. Gehrs. New York: Macmillan, 1917.

MLA (9th ed.) Citation

Gehrs, John Henry. Productive Agriculture: By John H. Gehrs. Macmillan, 1917.