1. See for example,M. Ikeda, S. Ogawa andY. Ohnuki:Progr. Theor. Phys.,22, 715 (1959) and23, 1073 (1960). In these papers the Sakata model is investigated.
2. M. Gell-Mann: Report CTSL-20, California Institute of Technology, Pasadena;Y. Ne'eman:Nucl. Phys.,26, 222 (1961).
3. H. Weyl:The Classical Groups, 2nd ed. (Princeton, 1946), pp. 132–135.
4. See, for example,G. Racah:Group Theory and Spectroscopy, lectures 3 and 4 (Mimeographed notes byE. Merzbacher andD. Park, 1951).
5. J. E. Wess:Nuovo Cimento,15, 52 (1960).