1. White, J. R., and Cameron, A. E., Phys. Rev., 74, 991 (1948).
2. Bainbridge, K. T., and Nier, A. O., “Relative Isotopic Abundances of the Elements”, Preliminary Report 9, Nuclear Science Series (Nat. Res. Council, Washington, D.C.).
3. Stehn, J. R., and Clancy, E. F., “Chart of the Nuclides” (Knolls Atomic Power Laboratory, G.E. Company of America).
4. Hess, D. C., Marshall, R. R., and Urey, H. C., Science, 126, 1291 (1957).
5. Paul, W., Naturwiss., 31, 419 (1943).