APA-referens (7:e uppl.)

Barrett, O. W. (1928). The tropical crops. The Macmillan Company.

Chicago-referens (17:e uppl.)

Barrett, Otis Warren. The Tropical Crops. New York: The Macmillan Company, 1928.

MLA-referens (9:e uppl.)

Barrett, Otis Warren. The Tropical Crops. The Macmillan Company, 1928.