1. Allison, J. R. (1957). J.S.C. med. Ass., 53, 208.
2. Skin Diseases in General Practice;Bettley, F.R.,1949
3. Finnie, J. S. (1960). Brit. J. industr. Med., 17, 130.
4. Heilier, F. F. (1958). Brit. med. J., 1, 196.
5. Trans. and 23rd Ann. Rep. St John's Hosp;Homer, S.G.,1934