1. J.D. Jackson, Classical Electrodynamics (John Wiley and Sons, 1975).
2. H. Goldstein, Classical Mechanics, 2nd edition (Addison-Wesley, 1980).
3. P.A.M. Dirac, Rev. Mod. Phys. 21, 392 (1949).
4. P.A.M. Dirac, Proc. Roy. Soc. London A 167, 148 (1938).
5. W. Pauli, Theory of Relativity (Pergamon, N.Y., 1958).