1. Roger G. Newton,Scattering Theory of Waves and Particles(McGraw-Hill, New York, 1966), Chap. 12, Sec. 12.1.2, P. 340.
2. See Ref. 1, p. 331.
3. See Ref. 1, p. 373.
4. Leonard I. Schiff,Quantum Mechanics(McGraw-Hill, New York, 1955), 2nd ed., Chap. 4, pp. 77–9.
5. See Ref. 1, Chap. 12.