1. Ashley, D.J.B. 1986. Welshness and Disease.In Genetic and Population Studies in Wales P. S. Harper and E. Sunderland, eds. Pp. 290–316. Cardiff; University of Wales Press.
2. Ashley, D.J.B. and H.D. Davies, 1966. The Use of Surnames as a Genetic Marker in Wales. British Journal of Medical Genetics 3; 203–211.
3. Bannister A.T., 1929. Visitation Returns of the Diocese of Hereford in 1397. English Historical Review 44; 279–289.
4. Bardsley, C.W., 1901 Dictionary of English and Welsh Surnames. London: Chatto and Windus, (reprint 1968) Reprinted Baltimore; Genealogical Printing Company.
5. Baxter, J.H., 1875. Statistics, Medical and Anthropological of the Provost-Marshal General's Bureau. United States Government.