Lightbown, P. M., & Spada, N. (1999). How languages are learned (2a. ed.). Oxford University.
Chicago-čujuhus (17. p.)Lightbown, Patsy M., juo Nina Spada. How Languages Are Learned. 2a. ed. Oxford: Oxford University, 1999.
MLA-čujuhus (9. p.)Lightbown, Patsy M., juo Nina Spada. How Languages Are Learned. 2a. ed. Oxford University, 1999.
Muitte dárkkistit čujuhemiid riektatvuođa, ovdal go geavahat daid iežat deavsttas.