↑ The Essence of Anthropology 3rd ed. By William A. Haviland, Harald E. L. Prins, Dana Walrath, Bunny McBrid. Pg 83.
↑ Race and Human Evolution. By Milford H. Wolpoff. p. 348.
↑ Vanishing Voices : The Extinction of the World's Languages. By Daniel Nettle, Suzanne Romaine Merton Professor of English Language University of Oxford. pp. 102–103.
↑ Cook, M (2007). “The clay loom weight, in: Early Neolithic ritual activity, Bronze Age occupation and medieval activity at Pitlethie Road, Leuchars, Fife”. Tayside and Fife Archaeological Journal. 13: 1–23.
1 2 This is indicated by the M130 marker in the Y chromosome. "Traces of a Distant Past," by Gary Stix, Scientific American, July 2008, pages 56-63.
↑ Gene S. Stuart, "Ice Age Hunters: Artists in Hidden Cages." In Mysteries of the Ancient World, a publication of the National Geographic Society, 1979. Pages 11-18.
↑ Stuart, Gene S. (1979). “Ice Age Hunters: Artists in Hidden Cages”. Mysteries of the Ancient World. National Geographic Society. tr. 8–10.
↑ "Shift from Savannah to Sahara was Gradual," by Kenneth Chang, New York Times, ngày 9 tháng 5 năm 2008.
↑ Kiple, Kenneth F. and Ornelas, Kriemhild Coneè, eds., The Cambridge World History of Food, Cambridge University Press, 2000, p. 83
↑ "No-Till: The Quiet Revolution," by David Huggins and John Reganold, Scientific American, July 2008, pages 70-77.
↑ Fagan, Brian M, ed. The Oxford Companion to Archaeology, Oxford University Press, Oxford 1996 ISBN 978-0-521-40216-3 p 363
↑ Glassner, Jean-Jacques. The Invention of Cuneiform: Writing In Sumer. Trans.Zainab,Bahrani. Baltimore: The Johns Hopkins University Press, 2003. Ebook.
↑ Caroline Alexander, "Stonehenge," National Geographic, June 2008.
