1. Majer, J. R., and Patrick, C. R., Nature, 192, 866 (1961).
2. Margrave, J. L., Nature, 197, 376 (1963).
3. Park, J. D., Benning, A. F., Downing, F. B., Lancery, J. F., and McHarneas, R. C., Indust. Eng. Chem., 39, 354 (1947).
4. Hudlicky, M., Chemistry of Organic Fluorine Compounds, 268 (Pergamon Press, London, 1961).
5. Norton, F. J., Refrigerating Engineering, 33 (September, 1957).