1. K. Schwarz. CRC Critical Reviews in Solid State and Materials Sciences, 13, 11 (1987); and references therein.
2. A. Neckel. Int.. J. Quantum Chem., 23, 1317 (1983).
3. L.I. Johansson and C.G. Larsson. Angle Resolved Photoemission, S.D. Kevan, Ed., (Springer, 1992), Chap. 8; and references therein.
4. L.I. Johansson. Surf Sci. Reports, in press.
5. D. Spanjaard, C. Guillot, M.C. Desjonquèrès, G. Trèglia and J. Lacante. Surf. Sci. Reports, 5(1/2), (1985).