Cita APA (7th ed.)

Gairns R. Ruth & Redman S. Stuart. (2005). Natural English. Pre-intermediate: Teacher's book. New York, Oxford University Press, 2005.

Cita Chicago (17th ed.)

Gairns R. Ruth i Redman S. Stuart. Natural English. Pre-intermediate: Teacher's Book. New York, Oxford University Press, 2005, 2005.

Cita MLA (9th ed.)

Gairns R. Ruth i Redman S. Stuart. Natural English. Pre-intermediate: Teacher's Book. New York, Oxford University Press, 2005, 2005.