Williams. Proof. University of North Texas Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रWilliams. Proof. University of North Texas Press.
एमएलए (9वां संस्करण) प्रशस्ति पत्रWilliams. Proof. University of North Texas Press.
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