1. R. D. Peccei:Proceedings of the XVII Ecole d'Eté de Physique de Particules, Clermont Ferrand, France, September 1985; Phys. Lett. B,124, 67 (1983).
2. H. Harari: SCAC Summer Institutes (1980), p. 141 and (1981), p. 685,Are Quarks end Leptons composite? (Weizmann preprint 4, WIS/82/1).
3. N. Ohtsubo andH. Miyata:Phys. Lett. B,169, 487 (1987).
4. M. Kaluža andN. Mankoč-Borštnik:Nuovo Cimento A,101, 71 (1989).
5. N. Mankoč-Borštnik:The Size of Systems in Massless Collective States (preprint IC/1989/109).