<p>Berrill, op. cit., p. 168.</p>

<p>Robert F. Spencer, Jesse D. Jennings' et al., The Native Americans (New York: Harper &amp; Row, 1965), p. 298.</p>

<p>Ibid., p. 168.</p>

<p>Ibid., p. 169.</p>

<p>Ibid.</p>

<p>Ibid., p. 159.</p>

<p>N. J. Berrill, Man's Emerging Mind (London: Dennis Dobson, 1958), p. 170.</p>

<p>Ibid., p. 122.</p>

<p>Hawkes and Woolley, op. cit., p. 264.</p>

<p>Evans-Pritchard, op. cit., pp. 50-51.</p>