Beiglboeck, W.; Boehm, A.; Takasugi, E. (eds.); International Union of Pure and Applied Physics; National Science Foundation, Washington, DC (USA); Department of Energy, Washington, DC (USA); Lecture notes in physics; no. 94; p. 254; ISBN 3-540-09238-2; ; 1979; p. 254; Springer; Berlin, Germany, F.R; 7. international group theory colloquium and integrative conference on group theory and mathematical physics; Austin, TX; 11 - 16 Sep 1978; Short communication only.