1. Junge, C. E., in Air Chemistry and Radioactivity (Academic Press Inc., New York, 1963).
2. Cultrera, R., Gazz. Chim. Ital., 66, 440 (1936).
3. Villars, D. S., J. Amer. Chem. Soc., 49, 326 (1927).
4. Cultrera, R., Gazz. Chim. Ital., 76, 187 (1946).
5. Cultrera, R., and Ferrari, G., Ann. Chim., 47, 1321 (1957).