1. B.63, 2428 (1930).
2. Mikrochemie18, 66 (1935);
3. N. S. Poluektof, Ztschr. analyt. Chem.105, 24.
4. I. P. Alimarin a.V. Zverev, Colorimetric Determination of Small Quantities of Silica in Solutions, Minerals and Technical products. Transactions of the Institute of Economic Mineralogy, Moscow (1935).
5. Electrochem. Soc. 191 (1933).