Gifford. How We Became Human. Michigan State University Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रGifford. How We Became Human. Michigan State University Press.
एमएलए (9वां संस्करण) प्रशस्ति पत्रGifford. How We Became Human. Michigan State University Press.
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