1. Herrnstein, R. J. I.Q. in the Meritocracy (Lane, London, 1973).
2. Jensen, A. R. Educability and Group Differences (Constable, London, 1973).
3. Thoday, J. M. & Gibson, J. B. Science 167, 990–992 (1970).
4. Halsey, A. H. Br. J. Sociol. 9, 15–28 (1958).
5. Mourant, A. E., Kopeć, A. C. & Domaniewska-Sobczak, K. The Distribution of the Human Blood Groups and Other Polymorphisms (Oxford Medical, London, 1976).