Cofman, J. (1995). Numbers and shapes revisited: More problems for young mathematicians. Clarendon Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रCofman, Judita. Numbers and Shapes Revisited: More Problems for Young Mathematicians. Oxford, [Eng.]: Clarendon Press, 1995.
एमएलए (9वां संस्करण) प्रशस्ति पत्रCofman, Judita. Numbers and Shapes Revisited: More Problems for Young Mathematicians. Clarendon Press, 1995.
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