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2. R.A. Bertlmann, G. Launer, E. de Rafael: Nucl. Phys.B250, 61 (1985)
3. C.A. Dominguez, E.de Rafael: Marseille Report (1986)
4. H. Fritzsch, M. Gell-Mann: Proc. 16th International Conference on High Energy Physics Vol. 2, (FNAL, Batavia, 1972); H. Fritzsch, P. Minkowski: Nuovo CimentoA30, 393 (1975)
5. For reviews see e.g.: S.R. Sharpe: Harvard Report No. 84-416 (1984); M.S. Chanowitz: LBL Report No. LBL-18701 (1984); T. Barnes: Rutherford Report No. RAL-85-005 (1985)