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2. E. Schrödinger:Proc. Boy. Irish Acad.,46 A, 9 (1940);46 A, 180 (1941);47 A, 53 (1941).
3. I. I. Goldman andV. D. Krivchenkov:Problems in Quantum Mechanics (London, 1961), pp. 52 and 53.
4. R. D. Evans:Atomic Nucleus (New York, 1955), p. 398.