APA (7th ed.) Citation

Oxenden, C., Latham-Koenig, C., & Seligson, P. (2008). American English file. Oxford University Press.

Chicago Style (17th ed.) Citation

Oxenden, Clive, Christina Latham-Koenig, and Paul Seligson. American English File. New York,USA ; Oxford, United Kingdom: Oxford University Press, 2008.

MLA (9th ed.) Citation

Oxenden, Clive, et al. American English File. Oxford University Press, 2008.