Knutson, J.W. : An Evaluation of the Effectiveness as a Caries Control Measure of the Topical Application of Solutions of Fluorides, J. D. Res. 27: 340, 1948.
2.
Armstrong, W.D. : Modification of the Willard-Winter Method for Fluorine Determination, J. A. C. S. 55: 1741, 1933 .
3.
Willard, H.H. , and Winter, O.B.: Volumetric Method for Determination of Fluorine, Indust. & Engin. Chem. (Indust. Ed.)5: 7, 1933.
