1. N. Cabibbo, L. Horwitz andY. Ne'eman: CERN preprint TH. 680, to be published inPhys. Lett. Hereafter referred to as I.
2. I. Fleming: for instance,In Her Majesty's Secret Service (London, 1963). The relevance of the Bond factor in quantum electrodynamics has been previously noted byB. Touschek (private communication).
3. D. Perkins: Berkeley High-Energy Physics Study, UCRL 10022 (1962).
4. W. Galbraith,et al.:Phys. Rev.,138, B 913 (1965).
5. V. Barger andM. Olsson: University of Madison preprint.