1. Terlet, H., and Briau, A., Ann. Falsific., 28, 546 (1935).
2. Gisiger, L., Z. anal. Chem., 115, 15 (1938).
3. Thistlethwaite, W. P., Analyst, 72, 531 (1947).
4. Wells, A. F., “Structural Inorganic Chemistry”, p. 351, 2nd edit. (Clarendon Press, Oxford, 1950).
5. Kayas, G., J. Chim. Phys., 47, 408 (1950).