1. Souriau, J. M.: Commun. Math. Phys.1, 374 (1966).
2. Streater, R. F.: Commun. Math. Phys.2, 354 (1966).
3. Dirac, P. A. M.: Quantum mechanics, 4th Ed., Chap. IV, pp. 84–89. Oxford: Clarendon Press 1958.
4. Abraham, R.: Foundations of mechanics, Chap. IV, pp. 132–153. New York: W. A. Benjamin 1967.
5. Shewell, J. R.: Am. J. Phys.27, 16 (1959).