1. M. C. AGNEW, G. B. AGNEW, and F. F. TISDALL : Journ. Amer. Dent. Ass.1933 , p.195 .
2. S. N. BLACKBEBG, and J. D. BKRKE : Dental Caries experimentelly produced in the Rat . Journ. Dent. Res.1932 , p.609 .
3. R. W. BUNTING : Journal Amer. Dent. Ass.1933 , p.773 .