APA Style

Trask,R.L. (2010). Why do language changes? . New York: Cambrige University Press.

Chicago Style

Trask,R.L. Why do language changes?. New York: Cambrige University Press, 2010. Text.

MLA Style

Trask,R.L. Why do language changes?. New York: Cambrige University Press, 2010. Text.

Turabian Style

Trask,R.L. Why do language changes?. New York: Cambrige University Press, 2010. Print.