Gairns, R., & Redman, S. (2003). Natural English: Upper-intermediate student's book. Oxford University Press.
Čikaški stil citiranja (17. izdanje)Gairns, Ruth, i Stuart Redman. Natural English: Upper-intermediate Student's Book. Oxford: Oxford University Press, 2003.
MLA način citiranja (8. izdanje)Gairns, Ruth, i Stuart Redman. Natural English: Upper-intermediate Student's Book. Oxford University Press, 2003.
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