APA (7th ed.) Citation

Radley, P., Simons, D., & Campbell, C. (2009). Horizons. Oxford University Press.

Chicago Style (17th ed.) Citation

Radley, Paul, Daniela Simons, and Colin Campbell. Horizons. Oxford: Oxford University Press, 2009.

MLA (9th ed.) Citation

Radley, Paul, et al. Horizons. Oxford University Press, 2009.