1. Allen, M. J., Boyland, E., Dukes, C. E., Horning, E. S. and Watson, J. G., British J. Cancer 11, Page 212, 1957.
2. Kuznezova, L. E., Nature 222, Page 484, 1969.
3. Nettleship, A., Henshaw, P. S. and Meyer, H, C., J. National Cancer Institute 4, Page 309, 1943.
4. Rogers, S., J. Exp. Medicine 93, Page 427, 1951.
5. Rogers, S., J. Exp. Medicine 105, Page 279, 1957.