Dyfyniad APA

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

Dyfyniad Arddull Chicago

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

Dyfyniad MLA

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

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.