1. Boring, E. G. (1923, June 6). Intelligence as the tests test it. New Republic, 35–37.
2. Carroll, J. B. (1993). Human cognitive abilities: A survey of factor-analytic studies. New York: Cambridge University Press.
3. Cattell, R. B. (1971). Abilities: Their structure, growth and action. Boston: Houghton Mifflin.
4. Cattell, R. B., & Cattell, H. E. P. (1973). Measuring intelligence with the Culture Fair Tests. Champaign: Institute for Personality and Ability Testing.
5. Ceci, S. J. (1996). On intelligence (Rev. and exp. ed.). Cambridge, MA: Harvard University Press.