1. Smith, F. A., and Hodge, H. C., in Fluorine and Dental Health (Staples Press, London, 1960).
2. Proffit, W. R., and Ackerman, J. L., Science, 145, 932 (1964).
3. Roholm, K., Fluoride Intoxication, A Clinical Hygienic Study with a Review of the Literature and some Experimental Observations (H. K. Lewis and Co., London, 1937).
4. Frajola, W. J., in Fluorine and Dental Health (Staples Press, London, 1960).
5. Faccini, J. M. (to be published).