1. Eaton, Shostak, and Konner 1988a; Eaton, Shostak, and Konner 1988b, p. 69; Andrews and Martin 1992, p. 41; Foley 1995, p. 59.
2. Andrews and Martin 1992, p. 41; Eaton, Shostak, and Konner 1988b, p. 70.
3. Eaton, Shostak, and Konner 1988b, p. 70; Eaton, Shostak, and Konner 1988a.
4. Eaton and Konner 1985, p. 284 (chart); Eaton, Shostak, and Konner 1988b, p. 20; Groves 1993, pp. 42-43.
5. Groves 1993, pp. 42-43; Foley 1995, pp. 58, 70.