Cita APA (7th ed.)

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

Cita Chicago (17th ed.)

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

Cita MLA (9th ed.)

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