APA (7th ed.) Citation

Purves, W. K., Sadava, D., Orians, G. H., & Heller, H. C. Life: The science of biology (Seventh edition.).

Chicago Style (17th ed.) Citation

Purves, William K., David Sadava, Gordon H. Orians, and H. Craig Heller. Life: The Science of Biology. Seventh edition.

MLA (9th ed.) Citation

Purves, William K., et al. Life: The Science of Biology. Seventh edition.