1. Stohlman, jun., F., and Brecher, G., Proc. Soc. Exp. Biol. and Med., 100, 40 (1959).
2. Jacobson, L. O., Goldwasser, E., and Gurney, C. W., in The Kinetic of Cellular Proliferation, edit. by Stohlman, jun., F., 344 (Grune and Stratton, New York, 1959).
3. Hammond, G. D., Ishikawa, A., and Keighley, G., in Erythropoiesis, edit. by Jacobson, L. O., and Doyle, M., 351 (Grune and Stratton, New York, 1962).
4. DeGowin, R. L., Hofstra, D., and Gurney, C. W., J. Lab. Clin. Med., 60, 846 (1962).
5. Naets, J. P., and Wittek, M., Nature, 206, 726 (1965).