1. P.M. Echenique, J.B. Pendry, J. Phys. C 11, 2065 (1978)
2. N.V. Smith, Phys. Rev. B 32, 3549 (1985)
3. T. Fauster, W. Steinmann, Photonic Probes of Surfaces, vol. 2, in Electromagnetic Waves: Recent Developments in Research, ed. by P. Halevi (North-Holland, Amsterdam, 1995), chap. 8, p. 347
4. M. Weinelt, J. Phys.: Condens. Matter 14, R1099 (2002)
5. R.M. Osgood, X.Y. Wang, Solid State Phys. 51, 1 (1998)