1. M. Gell-Mann:Phys. Rev. Lett.,14, 77 (1965);Y. Dothan, M. Gell-Mann andY. Ne’Eman:Phys. Lett.,17, 148 (1965);Y. Dothan andY. Ne’eman:Symmetry Groups in Nuclear and Particle Physics, edited byF. J. Dyson (New York, 1966), p. 287.
2. B. T. Feld:Models of Elementary Particles, Chap. 16 (Waltham, Mass., 1969).
3. For example, seeF. J. Gilman:Current problems and future directions in meson spectroscopy: theory, on page 460 ofAIP Conference Proceedings, No. 8,Particles and Fields Subseries, No. 3,Experimental Meson Spectroscopy, 1972, edited byA. H. Rosenfeld andK. W. Lai.
4. L. C. Biedenharn, R. Y. Cusson, M. Y. Han andO. L. Weaver:Phys. Lett.,42 B, 257 (1972).
5. O. L. Weaver andL. C. Biedenharn:Phys. Lett.,32 B, 326 (1970);Nucl. Phys.,185 A, 1 (1972).