1. Ali, M.H., Atiqur Rahman, H.: Int. J. Theor. Phys. 48, 1717 (2009)
2. Arnowitt, R., Deser, S., Misner, C.W.: Gravitation: An Introduction to Current Research. Wiley, New York (1962)
3. Buzzi, V., Hines, K.C., Treumann, R.A.: Phys. Rev. D 51, 6663 (1995a)
4. Buzzi, V., Hines, K.C., Treumann, R.A.: Phys. Rev. D 51, 6677 (1995b)
5. Das, A.C.: Space Plasma Physics: An Introduction, p. 75. Narosa, New Dehli (2004)