APA (7th ed.) Citation

De Villiers, J. G., & Villiers, P. A. d. (1978). Language acquisition. Harvard Univ. Press.

Chicago Style (17th ed.) Citation

De Villiers, Jill G., and Peter A. de Villiers. Language Acquisition. Cambridge, Mass: Harvard Univ. Press, 1978.

MLA (9th ed.) Citation

De Villiers, Jill G., and Peter A. de Villiers. Language Acquisition. Harvard Univ. Press, 1978.