Biddulph, Maj. J. Tribes of the Hindoo Koosh. 164 pp. Gov't. Printing Office. Calcutta, 1880.
Frazer, J.G. The Golden Bough: Part II, Taboo and the Perils of the Soul. 446 pp. Macmillan. London, 1911.
Webster, Hutton. Primitive Secret Societies. 227 pp. Macmillan. N.Y., 1908.