If you have trouble locating any of these papers please contact an author for a reprint. A few of the later G.P. Srivastava Group papers are available as on line Postscript documents.
G P Srivastava
J Phys C 10, 1843-1854 (1977).
G P Srivastava
J Phys C 10, L63- (1977).
M Jaros and G P Srivastava
J Phys Chem Solids 38, 1399-1401 (1977).