1. R. Abrams, Experientia, 3, 488 (1947).
2. J. D. Cox and R. J. Warne, J, Chem. Soc.,1951, 1893.
3. N. P. Keier, B. V. Klimenok, and G. V. Isagulyants, Dokl. AN SSSR,85, 1029 (1952).
4. H. H. Inhoffen, U. Schwieter, C. O. Chichester, and G. McKinney, J. Amer. Chem. Soc.,77, 1953 (1955).
5. ?Methods for the Preparation and Measurement of Radioactive Compounds? [in Russian], Collection of Papers, Editor-in-Chief V. V. Bochkarev, Moscow (1960).