1. L. D. Landau and E. M. Lifshitz, Course of Theoretical Physics, Vol. 3: Quantum Mechanics: Nonrelativistic Theory, Pergamon Press, New York (1973).
2. A. I. Baz, Ya. B. Zeldovich, and A. M. Perelomov, Scattering, Reactions and Decay in Non-relativistic Quantum Mechanics [in Russian], Nauka, Moscow (1971).
3. Contemporary Concepts in Physics;M. Moshinsky,1996
4. V. B. Berestetskii, E. M. Lifshits, and L. P. Pitaevskii, Course of Theoretical Physics, Vol. 4: Quantum Electrodynamics, Pergamon, New York (1982).
5. H. Yukawa, “Structure and mass spectrum of elementary particles. II. Oscillator model,” Phys. Rev., 91, 416–417 (1953).