1. Brooker, V. M. (1946). Med. J. Aust., 2, 595.
2. Cabot, R. C. (1923). J. Amer. med. Ass., 81, 298.
3. Cabot, R. C., and Dodge, H. F. (1925). Ibid., 84, 1793.
4. Gamble, C. J. (1924). Ibid., 83, 1230.
5. Gamble, C. J., and Replogle, D. E. (1924). Ibid., 82, 387.