Cita APA (7a ed.)

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

Cita Chicago Style (17a ed.)

Radley, Paul, y Daniela Simons. Horizons. Oxford: Oxford University Press, 2009.

Cita MLA (9a ed.)

Radley, Paul, y Daniela Simons. Horizons. Oxford University Press, 2009.