Birkin, J. (2012). Business Advantage: Upper-intermediate Teacher's book. Cambridge: Cambridge University Press.
शिकागो स्टाइल उद्धरणBirkin, Jonathan. Business Advantage: Upper-intermediate Teacher's Book. Cambridge: Cambridge University Press, 2012.
एमएलए उद्धरणBirkin, Jonathan. Business Advantage: Upper-intermediate Teacher's Book. Cambridge: Cambridge University Press, 2012.
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