APA (7th ed.) Citation

Fitter, R. (1966). Collins pocket guide to British birds (Revised ed.). Collins.

Chicago Style (17th ed.) Citation

Fitter, Richard. Collins Pocket Guide to British Birds. Revised ed. London: Collins, 1966.

MLA (9th ed.) Citation

Fitter, Richard. Collins Pocket Guide to British Birds. Revised ed. Collins, 1966.