Fredrik Barth, Nomads of South Persia (Boston: Little Brown, 1961), p. 6; Patty J. Watson, Archaeological Ethnography in Western Iran (Tucson: Univ. of Arizona, 1979), pp. 247–252; Douglas Johnson, The Nature of Nomadism (Chicago: Univ. of Chicago, 1969), pp. 40–46; Ofer Bar-Yosef, “Early Nomads in Southern Sinai,” National Geographic Research Reports—1976 Projects (1983), pp. 147–159.