1. Surface Enhanced Raman Scattering,1982
2. Electronic surface state contribution to surface enhanced Raman scattering
3. see also, A. Otto, in: Light Scattering in Solids, Vol. 4, Eds. M. Cardona and G. Güntherrodt (Springer, New York, in press).
4. T.E. Furtak and H. Macomber, preprint.
5. H. Ueba, Surface Sci., submitted.