1. For a review see the lectures by J. Ellis, L. Lederman, C. Llewellyn-Smith, J. Steinberger and B. Wiik, these Proceedings and references quoted therein.
2. C.N. Yang and R.J. Hills, Phys. Rev. 96, 191 (1954). G. ’t Hooft, Nuclear Phys. B35, 167 (1971 S.L. Glashow, J. Iliopoulos and L. Maiani, Phys. Rev. D2, 1285 (1970).
3. We assume that the heavy lepton T- is accompanied by its own neutrino. For a discussion of this point see the lectures by J. Ellis and B. Wiik in these Proceedings. The discovery of the T- is due to M. Perl et al., Phys. Rev. Letters 35, 1489 (1975)
4. We assume of course that the new quark which builds up the Y(9.6) appears in three colours. For the discovery of the Y(9.6) see the lectures by L. Lederman in these Proceedings.
5. H. Fritzsch, M. Gell-Mann, and H. Leutwyler, Phys. Lett. B47, 365 (1973). D. J. Gross and F. Wilczek, Phys. Rev. D8, 3497 (1973). S. Weinberg, Phys. Rev. Letters 31, 494 (1973).