APA (7th ed.) Citation

Onley, D. J., & Scofield, R. P. (2007). Field guide to the albatrosses, petrels and shearwaters of the world. Christopher Helm.

Chicago Style (17th ed.) Citation

Onley, Derek J., and R. Paul Scofield. Field Guide to the Albatrosses, Petrels and Shearwaters of the World. London: Christopher Helm, 2007.

MLA (9th ed.) Citation

Onley, Derek J., and R. Paul Scofield. Field Guide to the Albatrosses, Petrels and Shearwaters of the World. Christopher Helm, 2007.