Cita APA (7th ed.)

Gairns R. Rith & Redman S. Stuart. (2010). Natural English. Upper-intermediate: Student's book. New York, Oxford University Press, 2010.

Cita Chicago (17th ed.)

Gairns R. Rith i Redman S. Stuart. Natural English. Upper-intermediate: Student's Book. New York, Oxford University Press, 2010, 2010.

Cita MLA (9th ed.)

Gairns R. Rith i Redman S. Stuart. Natural English. Upper-intermediate: Student's Book. New York, Oxford University Press, 2010, 2010.