1. Ashburner, J. V. (1950). Med. J. Aust., 37 (2), 386.
2. Cade, J. F. J. (1949). Ibid., 36 (2), 349.
3. Carrere, J., and Pochard (1954). Ann med.-psychol., 112 (1), 566.
4. Cleaveland, S. A. (1913). J. Amer. med. Ass., 60, 722.
5. Corcoran, A. C., Taylor, R. D., and Page, I. H. (1949). Ibid.. 139,685.