1. E. Inonu and E. P. Wigner, Proc. Natl. Acad. Sci. USA 39, 510 (1953);
2. J. D. Talman, Special Functions, A Group Theoretical Approach Based on Lectures by E. P. Wigner (Benjamin, New York, 1968).
3. R. Gilmore, Lie Groups, Lie Algebras, and Some of Their Applications in Physics (Wiley, New York, 1974).
4. E.P. Wigner, Ann. Math. 40, 149 (1939);
5. V. Bargmann and E. P. Wigner, Proc. Natl. Acad. Sci. USA 34, 211 (1946);