1. Bayrd, E. D., And F. G. Heck: Proc. VI. Congr. Europ. Soc. Haematology Copenhagen 84–89, 1957.
2. Blachmann, S. S., And B. D. Davis: J. Clin.Invest. 22, 545 (1943).
3. Broch, O. J., And E. Brodwall: Acta med. scand. 5, 353 (1958).
4. Boyce, W. H., And F. K. Garvey: J. Clin. Invest. 33, 1287–1297 (1954).
5. Butler, E. A.: Lancet 1958, 978–980.