Cita APA (7th ed.)

Purves, W. K., & Orians,Gordon H. (1987). Life: The science of biology (2nd ed.). Sinauer.

Cita Chicago (17th ed.)

Purves, William K., i Orians,Gordon H. Life: The Science of Biology. 2nd ed. Massachusetts: Sinauer, 1987.

Cita MLA (9th ed.)

Purves, William K., i Orians,Gordon H. Life: The Science of Biology. 2nd ed. Sinauer, 1987.