APA (7th ed.) Citation

Lightbown, P. M., & Spada, N. M. (1993). How languages are learned. Oxford University Press.

Chicago Style (17th ed.) Citation

Lightbown, Patsy M., and Nina Margaret Spada. How Languages Are Learned. Oxford: Oxford University Press, 1993.

MLA (9th ed.) Citation

Lightbown, Patsy M., and Nina Margaret Spada. How Languages Are Learned. Oxford University Press, 1993.