Cita APA (7th ed.)

Ehrlich, P. R. (1987). The science of ecology. Macmillan.

Cita Chicago (17th ed.)

Ehrlich, Paul R. The Science of Ecology. New York: Macmillan, 1987.

Cita MLA (9th ed.)

Ehrlich, Paul R. The Science of Ecology. Macmillan, 1987.