1. Estimation of the direction and intensity of natural selection in relation to human intelligence by means of the intrinsic rate of natural increase;Bajema;Eugenics Quarterly,1963
2. Natural selection and intelligence: The relationship between intelligence and completed fertility among Third Harvard Growth Study participants;Bajema;American Journal of Physical Anthropology,1971
3. Is our national intelligence declining?;Cattell;The Eugenics Review,1936
4. The fight for our national intelligence;Cattell,1937
5. The fate of national intelligence: Test of a thirteen-year prediction;Cattell;The Eugenics Review,1951