1. R. J. Shamberger andD. V. Frost, Can. med. Ass. J.100, 682 (1969).
2. R. J. Savignac, J. C. Gant andI. W. Sizer, Am. Ass. adv. Sci. Res. Conference on Cancer,1945, p. 241–252.
3. Also seeR. J. Winzler, Adv. Cancer Res.1, 519 (1953).
4. M. M. Black andF. D. Speer, Am. J. clin. Path.20, 446 (1950).
5. N. Eriksen, L. D. Ellerbrook andS. W. Lippincott, J. Am. Cancer Inst.7, 705 (1951).