Cita APA (7th ed.)

Gairns R. Ruth & Redman S. Stuart. (2007). Natural English. Elementary: Student's book. New York, Oxford University Press, 2007.

Cita Chicago (17th ed.)

Gairns R. Ruth i Redman S. Stuart. Natural English. Elementary: Student's Book. New York, Oxford University Press, 2007, 2007.

Cita MLA (9th ed.)

Gairns R. Ruth i Redman S. Stuart. Natural English. Elementary: Student's Book. New York, Oxford University Press, 2007, 2007.