APA (7th ed.) Citation

Sampson, G., Gil, D., & Trudgill, P. (2009). Language complexity as an evolving variable. Oxford University Press.

Chicago Style (17th ed.) Citation

Sampson, Geoffrey, David Gil, and Peter Trudgill. Language Complexity as an Evolving Variable. Oxford: Oxford University Press, 2009.

MLA (9th ed.) Citation

Sampson, Geoffrey, et al. Language Complexity as an Evolving Variable. Oxford University Press, 2009.