APA (7th ed.) Citation

Graddol, D., Leith, D., & Swann, J. (1996). English: History, diversity, and change. Routledge.

Chicago Style (17th ed.) Citation

Graddol, David, Dick Leith, and Joan Swann. English: History, Diversity, and Change. London: Routledge, 1996.

MLA (9th ed.) Citation

Graddol, David, et al. English: History, Diversity, and Change. Routledge, 1996.