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.
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