Halleran. The Better Angels of Our Nature. The University of Alabama Press.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रHalleran. The Better Angels of Our Nature. The University of Alabama Press.
एमएलए (9वां संस्करण) प्रशस्ति पत्रHalleran. The Better Angels of Our Nature. The University of Alabama Press.
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