Cita APA (7th ed.)
Butterfiels, J. (2009). Oxford a-z of english usage. Oxford University Press.
Cita Chicago (17th ed.)
Butterfiels, Jeremy. Oxford A-z of English Usage. New Delhi: Oxford University Press, 2009.
Cita MLA (9th ed.)
Butterfiels, Jeremy. Oxford A-z of English Usage. Oxford University Press, 2009.
Atenció: Aquestes cites poden no estar 100% correctes.