Warshawsky, D. (1982). Spectrum 1: A communicative course in English. Regents Publishing Company.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रWarshawsky, Diane. Spectrum 1: A Communicative Course in English. N.York: Regents Publishing Company, 1982.
एमएलए (9वां संस्करण) प्रशस्ति पत्रWarshawsky, Diane. Spectrum 1: A Communicative Course in English. Regents Publishing Company, 1982.
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