1. D. Bohm, E. Schiller andR. Tiomno:Nuovo Cimento,1, 48 (1955).
2. H. Goldstein:Classical Mechanics (Cambridge Mass., 1950). See Chap. 4.
3. W. Pauli:Rev. Mod. Phys.,13, 203 (1941).
4. H. Weyl:Theory of Groups and Quantum Mechanics (New York, 1928). See p. 180.
5. F. D. Murnagham:The Theory of Group Representations (Baltimore, 1938). See p. 318.