1. Leon E. Stover and Harry Harrison, (eds.) Apeman, Spaceman, Berkeley Medallion Books, New York, (1970), pp. 330–381.
2. W. Farnsworth Loomis, “Skin Pigment Regulation of Vitamin-D Biosynthesis in Man”, Science, Vol. 157, (August, 1967), pp. 501–506.
3. Stanley M. Garn, Human Races, Charles C. Thomas, Springfield, I11. (1965).
4. Carleton S. Coon, The Study of Man, Alfred A. Knopt, New York, (1962).
5. The work of freelance artist Robert Bordeaux, 26817 Dix Court, Damascus, Maryland.