APA (7th ed.) Citation

Center for Applied Linguistics & Shopen, T. (1987). Languages and their speakers. University of Pennsylvania Press.

Chicago Style (17th ed.) Citation

Center for Applied Linguistics and Timothy Shopen. Languages and Their Speakers. Philadelphia: University of Pennsylvania Press, 1987.

MLA (9th ed.) Citation

Center for Applied Linguistics and Timothy Shopen. Languages and Their Speakers. University of Pennsylvania Press, 1987.