APA (7th ed.) Citation

Henry, G. M. (1971). A guide to the birds of Ceylon (2nd ed.). Oxford University Press.

Chicago Style (17th ed.) Citation

Henry, G. M. A Guide to the Birds of Ceylon. 2nd ed. London: Oxford University Press, 1971.

MLA (9th ed.) Citation

Henry, G. M. A Guide to the Birds of Ceylon. 2nd ed. Oxford University Press, 1971.