1. Localized Excitations in Solids;Bellomonte,1968
2. Optical studies of the vibrational properties of disordered solids
3. SHEN, S.C., FANG, J.C., CARDONA, M., and GENZEL, L., Phys. Rev., in press.
4. SHEN, S.C., FANG, J.C., and CARDONA, M., Phys. Rev., to be published.