1. Nettleship, A., and Henshaw, P. S., J. Nat. Cancer Inst., 4, 309(1943).
2. Mostofi, F. K., and Larsen, C. D., Amer. J. Path., 25, 807(1949).
3. Salaman, M. H., and Roe, F. J. C., Brit. J. Cancer, 7, 472 (1953).
4. Graffi, A., Vlamynck, K. E., Hoffmann, F., and Schulz, I., Arch. Geschwulsiforsch., 5, 110 (1953).
5. Tannenbaum, A., and Silverstone, H., Cancer Res., 18, 1225 (1958).