1. Bally, J. and Harrison, E. R.: 1978,Astrophys. J. 220, 943.
2. Eddington, A. S.: 1926,Internal Constitution of the Stars, Cambridge University Press, Cambridge, England.
3. Hughes, V. H.: 1964, in H. Y. Chiu and W. F. Hoffman (eds.),Gravitation and Relativity, Benjamin.
4. Lyttleton, R. A. and Bondi, H.: 1959,Proc. Roy. Soc. (London) A252, 313.
5. Mehra, A. L.: 1982,Phys. Lett. 88A, 159.