APA (7th ed.) Citation

Lightbown, P. M., & Spada, N. (1999). How languages are learned (2nd ed.). Oxford University Press.

Chicago Style (17th ed.) Citation

Lightbown, Patsy M., and Nina Spada. How Languages Are Learned. 2nd ed. Oxford: Oxford University Press, 1999.

MLA (9th ed.) Citation

Lightbown, Patsy M., and Nina Spada. How Languages Are Learned. 2nd ed. Oxford University Press, 1999.