[3] "The Mind of Primitive Man" by Franz Boas.
[4] "Children of the Slaves" by Stephen Graham.
[5] "Anthropological Notes on Bantu Natives from Portuguese East Africa" by C.D. Maynard, F.R.C.S.E., Statistician and Clinician to the South African Institute for Medical Research, and G.A. Turner, M.B., B.Ch., Aberdeen D.P.H., Medical Officer to the Witwatersrand Native Labour Association.
[6] "The Growth of the Brain" by H.H. Donaldson, Professor of Neurology in the University of Chicago.
[7] "The Mind of Primitive Man" by Franz Boas.
[8] "The Antiquity of Man" by Arthur Keith, M.D., LL.D., F.R.C.S., F.R.S.
[9] "Ancient Hunters" by W.J. Sollas, D.De., LL.D., Professor of Geology and Palæontology in the University of Oxford.
[10] "Anthropology" by R.R. Marett.
[11] "The Antiquity of Man" by Arthur Keith, M.D.
[12] "Initiative in Evolution" by Walter Kidd, M.D., F.R.S.E.