1. Brookhaven, lepton pair production experiment (private communication).
2. SPEAR (private communication).
3. Frascati, υυ2, MEA, pp groups (private communications to be published). ba](4){au{gnJ. D.} {fnBjorken}} and {au{gnS. L.} {fnGlashow}}: {jtPhys. Lett.}, {vn11}, {pp225} ({dy1964});S. Glashow, J. Iliopoulos andL. Maiani:Phys. Rev. D,2, 1285 (1970).
4. S. Weinberg,Phys. Rev. Lett.,19, 1264 (1967);A. Salam:Proceedings of the Eight Nobel Symposium (New York, N. Y., 1968).
5. Gargamelle Collaboration:Phys. Lett.,46 B, 138 (1973).