APA (7th ed.) Citation

Harper Collins, Hollom, P., Mountfort, G., & Peterson, R. (1993). Birds of Britain and Europe. Harper Collins.

Chicago Style (17th ed.) Citation

Harper Collins, P. Hollom, Guy Mountfort, and Roger Peterson. Birds of Britain and Europe. London: Harper Collins, 1993.

MLA (8th ed.) Citation

Harper Collins, et al. Birds of Britain and Europe. Harper Collins, 1993.