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.
A C Ferraz and G P Srivastava
Semicond Sci Technol 1, 169-171 (1986).
A C Ferraz and G P Srivastava
Surf Sci 182, 161-178 (1987).
A C Ferraz and G P Srivastava
Semicond Sci Technol 8, 67-72 (1993).