APA (7th ed.) Citation

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

Chicago Style (17th ed.) Citation

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

MLA (9th ed.) Citation

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