1. D. Littler, Proc. Phys. Soc.65A, 203 (1952).
2. K. A. Petrzhak, Physics of the Fission of Atomic Nuclei, Supplement No. 1 to Atomnaya Énergiya (1957).
3. E. Segré, Phys. Rev.86, 21 (1952).
4. J. Fraser, Proc. of the Symposium on the Phys. of Fission (Chalk River, Ontario, 1956) p. 238.
5. É. K. Gerling, Yu. A. Shukolyukov and B. A. Makarochkin, Radiokhimiya1, 223 (1959).