RICHARDS, R. (1991). An Early Start To Technology From Science Roy Richars. Simon and Schuster.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रRICHARDS, Roy. An Early Start To Technology From Science Roy Richars. Simon and Schuster, 1991.
एमएलए (8वां संस्करण) प्रशस्ति पत्रRICHARDS, Roy. An Early Start To Technology From Science Roy Richars. Simon and Schuster, 1991.
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