Gairns, R., & Redman, S. (2003). Natural English: Upper-intermediate student's book. Oxford University Press.
Chicago Style (17. basım) AtıfGairns, Ruth, ve Stuart Redman. Natural English: Upper-intermediate Student's Book. Oxford: Oxford University Press, 2003.
MLA (8th ed.) AtıfGairns, Ruth, ve Stuart Redman. Natural English: Upper-intermediate Student's Book. Oxford University Press, 2003.
Uyarı: Bu alıntı herzaman %100 doğru olmayabilir..