APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (8th ed.) Citation

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