1. S.D. Kevan (ed.): Angle-Resolved Photoemission, Studies in Surface Science and Catalysis, Vol. 74 (Elsevier, Amsterdam 1992)
2. P.M. Echenique, J.B. Pendry: J. Phys. C 11, 2065 (1978)
3. W. Steinmann, Th. Fauster: In Laser Spectroscopy and Photochemistry on Metal Surfaces, ed. by H.L. Dai, W. Ho (World Scientific, Singapore 1994)
4. N.V. Smith: Phys. Rev. B 32, 3549 (1985)
5. N.W. Ashcroft and N.D. Mermin: Solid State Physics (Saunders College, Philadelphia 1976) Chap. 8, Problem 1