APA (7th ed.) Citation

De Villiers, J. G., & Villiers, P. A. d. (1981). Language acquisition (6. print.). Harvard Univ. Press.

Chicago Style (17th ed.) Citation

De Villiers, Jill G., and Peter A. de Villiers. Language Acquisition. 6. print. Cambridge, Mass: Harvard Univ. Press, 1981.

MLA (9th ed.) Citation

De Villiers, Jill G., and Peter A. de Villiers. Language Acquisition. 6. print. Harvard Univ. Press, 1981.