1. SeeE. M. Corson:Introduction to Tensors, Spinors and Relativistic Wave Equations (London, Glasgow, 1954).
2. D. L. Pursey:Ann. of Phys.,32, 157 (1965).
3. R. Shaw:Nuovo Cimento,33, 1074 (1964).
4. H. J. Bhabha:Rev. Mod. Phys.,17, 200 (1945).
5. SeeN. Jacobson:Lie Algebras, Interscience Tracts in Pure and Applied Mathematics, No. 10 (New York, London, 1962), Theorem 11, p. 47.