Cita APA (7a ed.)

Ahlgren, G. (1956). Forage crops (2nd edition.). McGraw-Hill.

Cita Chicago Style (17a ed.)

Ahlgren, Gilbert. Forage Crops. 2nd edition. New York: McGraw-Hill, 1956.

Cita MLA (8a ed.)

Ahlgren, Gilbert. Forage Crops. 2nd edition. McGraw-Hill, 1956.