1. W. R. Mckinon, L. H. Greene, G. W. Hull andE. M. Vogel,Phys. Rev. B 36 (1987) 226.
2. J. M. Tarason, P. Barboux, P. F. Micell, G. W. Greene-Hull, M. Eibshutz andS. A. Sunshine,ibid. 37 (1987) 7458.
3. A. Memon, M. N. Khan, C. D. Potter andD. B. Tanner,Modern Phys. Lett. B 4 (1990) (1351).
4. M. N. Khan, A. Memon, S. Al-Dallal andS. Chudasama,Physica C 1 (1994) 235.
5. M. N. Khan, S. Al-Dallal andA. Memon, in ?Proceedings of the Third International Symposium on Advanced Materials?, 20?24 September edited by Drs. A. Haq, F. Habibry and A. Q. Khan (Ferozsons Rawalpindi, Islamabad, Pakistan, 1993) p. 196.