1. Ardener, E. 1974 Social anthropology and population, in Parry, H. (ed.) Population and its Problems. Oxford University Press: Oxford, pp. 25–50.
2. Barbujani, G., & Sokal, R. 1990 Zones of sharp genetic change in Europe are also linguistic boundaries. Proceedings of the National Academy of Sciences of the United States of America 87: 1816–19.
3. Boyce, A.J., Kchemann, C.F., & Harrison, G.A. 1968 The reconstruction of historical movement patterns, in Acheson, E.D. (ed.) Record Linkage in Medicine. Livingstone: Edinburgh, pp. 303–19.
4. Chakraborty, R., & Weiss, K.M. 1982 Comments to N.E. Morton et al. Current Anthropology 23: 163–4.
5. Chapman, M.K. (ed.) 1993 Social and Biological Aspects of Ethnicity. Oxford University Press: Oxford.