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2. Goldstein, H. (1959).Classical Mechanics. Addison Wesley, Reading, Massachusetts.
3. Jammer, M. (1966).The Conceptual Development of Quantum Mechanics. McGraw-Hill, New York.
4. Landau, L., and Lifshitz, L. (1958).Quantum Mechanics. Addison Wesley, Reading, Massachusetts.
5. Liboff, R. L. (1975).Foundations of Physics,5, 271; see also, ?On the Validity of the Bohr Correspondence Principle,? to be published in,Annals de la Fondation L. de Broglie, Paris.