1. D. L. Weaver, C. L. Hammer andE. H. Good jr.:Phys. Rev.,135, B 241 (1964).
2. See, for example,P. Roman :Theory of Elementary Particles, 2nd. ed. (Now York, 1961), p. 111.
3. Ref. (2), p. 286.
4. A. Sankakanarayanan andK. H. Good jr.: (to be published).
5. See, for example,L. I. Schiff:Quantum Mechanics, 2nd ed. (New York, 1955), p. 146.