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3. H. A. Bethe, Intermediate Quantum Mechanics (W. A. Benjamin, New York, 1964).
4. P. A. M. Dirac, The Principles of Quantum Mechanics (Clarendon Press, Oxford, 1947).
5. L. D. Landau and E. M. Lifshitz, Quantum Mechanics: Non-Relativistic Theory. Course of Theoretical Physics, Vol. 3, Addison-Wesley Series in Advanced Physics (Pergamon, Reading; Addison-Wesley, London-Paris, 1958).