1. Sellin, Thorsten. 1938.Culture Conflict and Crime, 57–57. New York: Social Science Research Council.
2. Venter, Herman. 1966.Kriminologie, 108–108. Pretoria: Craft Pers Bpk.
3. Reuter, E.B. 1927.The American Race Problem, 353–353. New York: Cromwell.
4. English, H.B. and English, E.C. 1958.A Comparative Dictionary of Psychological Terms, 305–305. London: Longmans.
5. Mann, J.W. 1957.The problem of the Marginal Personality: A Psychological study of a Coloured Group, 18–18. D. Phil -proefskrif, Universiteit van Natal. ongepubliseerde