1. Barrett, W. D., Miller, K. T., and Fessenmeyer, C. R. (1949). Surg. Gynec. Obstet., 89, 767.
2. Chirurgische Klinik Wien;Billroth, C.A.T.,1879
3. Hirschwald, Berlin. Cited by Eisenstaedt, J. S. (1938). J. Amer. med. Ass., 110, 2056.
4. Bugher, J. C. (1934). Amer. J. Cancer, 21, 809.
5. Burke, M. (1936). Ibid, 27, 316.