References
- United Nations , ed. 1949 . Demographic Yearbook
- United Nations , ed. 1949 . Demographic Yearbook
- United Nations , ed. 1920-47 . World Population Trends
- Badenhorst , L. T. 1950 . The future growth of the population of South Africa and its probable age distribution . Population Studies , IV ( I ) June
- Kuczynski , R. R. 1936 . Population Movements 95 – 95 .