1. C. Rubbia, P. Mntyre, D. Cline, Proc. Int. Neutrino Conference Aachen 1976 (Vieweg, Braunschweig 1977) p. 683.
2. S. Weinberg, Phys. Rev. Lett. 19 (1967) 1264
3. S.L. Glashow, Nucl. Phys. 22 (1961) 579
4. A. “Salam in Elementary Particle Theory”, ed. N. Svartholm (Almquist an Wikrell, Stockholm 1968), p. 367.
5. For a review, see lectures by G. Ecker at the 21.Int. üniversitätswochen für Kernphysik, Schladming, Acta Physica Austriaca, Suppl. XXIV, 3–62 (1982).