1. G. J. Lapeyre andJ. Anderson:Notes on the Sixth Annual Synchrotron Radiation Users Group Conference (Stoughton, Wisc., 1973), p. 22;G. J. Lapeyre, A. D. Baer, J. Anderson, J. C. Hermanson, J. A. Knapp andP. L. Gobby:Sol. State Comm.,15, 1601 (1974);
2. Z. Hurych, J. C. Shaffer, D. L. Davis, T. A. Knecht, G. J. Lapeyre, P. L. Gobby andJ. A. Knapp:Phys. Rev. Lett.,33, 830 (1974).
3. G. J. Lapeyre andJ. Anderson:Phys. Rev. Lett.,35, 117 (1975).
4. Multielectron interactions, such as the core-to-surface exciton resonance, also contribute to the spectra and are not described by the formulae of table I.
5. G. W. Gobeli, F. G. Allen andE. O. Kane:Phys. Rev. Lett.,12, 94 (1964);E. O. Kane:Phys. Rev. Lett.,12, 97 (1964).