APA (7th ed.) Citation

 Oxford Pub. (2011). Concise Oxford English Dictionary  (12th.). Oxford.

Chicago Style (17th ed.) Citation

 Oxford Pub. Concise Oxford English Dictionary . 12th. New York: Oxford, 2011.

MLA (9th ed.) Citation

 Oxford Pub. Concise Oxford English Dictionary . 12th. Oxford, 2011.

Warning: These citations may not always be 100% accurate.