1. Brill, D. R. and Cohen, J. M.: 1966,Phys. Rev. 143, 1011.
2. Chandrasekhar, S.: 1939,Introduction to the Theory ofStellar Structure, Dover, New York.
3. Cohen, J. M.: 1970,Int. J. Theor. Phys. 3, 207.
4. Colgate, S. A. and White, R. H.: 1966,Astrophys. J. 143, 626.
5. Landau, L. and Lifshitz, E. M.: 1971,The Classical Theory of Fields, 3rd ed., Addison-Wesley, Reading, Massachusetts.