1. Elsasser, W. M., J. Phys. et Radium, 4, 549 (1933); 5, 389, 635 (1934).
2. Mayer, M. Goeppert, Phys. Rev., 75, 1969 (1949).
3. Haxel, O., Jensen, J. H. D., and Suess, H. E., Phys. Rev., 75, 1766 (1949); Z. Physik, 128, 295 (1950).
4. Mayer, M. Goeppert, and Jensen, J. H. D., Elementary Theory of Nuclear Shell Structure, 58 (John Wiley and Sons, Inc., New York and London, 1955).
5. This theory is described in papers to be published in Phys. Rev. Letters, Proc. U.S. Nat. Acad. Sci., and Science.