1. V. P. Frolov and I. D. Novikov, Black Holes: Basic Concepts and New Developments (Birkhauser, New York-Boston-Heidelberg, 1997).
2. J. Stewart, Advanced General Relativity (Cambridge University Press, Cambridge, 1996).
3. L. P. Hugston and K. P. Tod, An Introduction to General Relativity (Cambridge University Press, Cambridge, 1994).
4. M. Ludvigsen, General Relativity. A Geometric Approach (Cambridge University Press, Cambridge, 1999).
5. R. K. Sachs and H. Wu, General Relativity for Mathematicians (Springer-Verlag, New York-Heidelberg-Berlin, 1977).