Cita APA (7th ed.)

Keeton, W. T. (1972). Elements of biological science (2nd ed.). W.W. Norton.

Cita Chicago (17th ed.)

Keeton, William T. Elements of Biological Science. 2nd ed. New York: W.W. Norton, 1972.

Cita MLA (9th ed.)

Keeton, William T. Elements of Biological Science. 2nd ed. W.W. Norton, 1972.