Doff, A., & Jones, C. (1997). Language in use: Upper-intermediate : classroom book (6th print.). Cambridge University Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रDoff, Adrian, और Christopher Jones. Language in Use: Upper-intermediate : Classroom Book. 6th print. Cambridge: Cambridge University Press, 1997.
एमएलए (8वां संस्करण) प्रशस्ति पत्रDoff, Adrian, और Christopher Jones. Language in Use: Upper-intermediate : Classroom Book. 6th print. Cambridge University Press, 1997.
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