1. The distribution of the sickle-cell trait in East Africa and elsewhere, and its apparent relationship to the incidence of subtertian malaria
2. 1940 Malaria and the Colonization of the Carolina Low Country. 1526-1696. The Johns Hopkins Press, Baltimore.
3. and 1950 Race … a study of the problems of race formation in man. C. C. Thomas, Springfield, Ill.
4. 1935 Documents Illustrative of the History of the Slave Trade to America. Carnegie Inst. Publ. no. 409. vol. IV.