1. J.K. Martin, A.J. Kox, R. Schulman, Vol. 6. The Collected Papers of Albert Einstein (Princeton University Press, New Jersey, 1996)
2. S.M. Carroll. Spacetime and Geometry (Addison Wesley, San Francisco, 2004)
3. R.M. Wald. General Relativity (University of Chicago Press, Chicago, 1984)
4. J.B. Hartle. Gravity: an Introduction to General Relativity (Addison-Wesley, San Francisco, 2003)
5. B.F. Schutz. A First Course in General Relativity (Cambridge University Press, New York, 2009)