Barber, T. X. (1993). The human nature of birds: A scientific discovery with startling implications. Penguin Books.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्रBarber, Theodore Xenophon. The Human Nature of Birds: A Scientific Discovery with Startling Implications. New York: Penguin Books, 1993.
एमएलए (9वां संस्करण) प्रशस्ति पत्रBarber, Theodore Xenophon. The Human Nature of Birds: A Scientific Discovery with Startling Implications. Penguin Books, 1993.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.