1. FISH, E. W. (1939), Journ. Amer. Dent. Assoc., 26, 691.
2. FISH, E. W. and MACLEAN, I. H. (1936), Brit. Dent. Journ., 61, 336.
3. OKELL, C. C. and ELLIOTT, S. D. (1935), Lancet, 2, 869.
4. ROUND, H., KIRKPATRICK, H. J. R. and HAILS, C. G. (1936), Proc. Roy. Soc. Med., 29, 1552. FISH FISH, E. W. E. W. (1938), (1935), LBraintc.etD,en2t,.
5. WILLCOX, W. H. 1921) Brit. Med. Journ., i) 804.