APA (7th ed.) Citation

Trask, R. L., & Millar, R. M. (2010). Why do languages change? Cambridge University Press.

Chicago Style (17th ed.) Citation

Trask, R. L., and Robert McColl Millar. Why Do Languages Change? Cambridge, New York: Cambridge University Press, 2010.

MLA (9th ed.) Citation

Trask, R. L., and Robert McColl Millar. Why Do Languages Change? Cambridge University Press, 2010.