1. Batchelor, R. C. L., Horne, G. O., and Rogerson, H. L. (1951). Lancet, 2, 195.
2. Bell, R. C. (1954). Ibid., 1, 13.
3. Bell, R. C. (1956). Ibid., 2, 439.
4. Carlquist, P. R., and Pontius, E. E. (1954). Med. Bull. U.S. Army Europe, 11, 79.
5. Christenson, W. N., Hedrick, G. W., and Schugmann, R. F. (1953).