1. W. Pauli, Theory of Relativity (Dover, 1958)
2. R.C. Tolman, The Theory of the Relativity of Motion (UC Berkeley Press, 1918)
3. B. Carter, H. Quintana, Proc. R. Soc. A 331, 57 (1972)
4. J. Kijowski, G. Magli, J. Geom. Phys. 9, 207 (1992)
5. D. Christodolou, Ann. Inst. Henri Poincare 69, 335 (1998)