1. D.J.Nagel: InBand Structure Spectroscopy of Metals and Alloys. ed. by D.J.Fabian and L.M.Watson (Academic Press, New York 1973) p. 457
2. G.Böhm, K.Ulmer: J. Physique, Colloque C4, C4–241 (1971)
3. K.Ulmer: InBand Structure Spectroscopy of Metals and Alloys, ed. by D.J.Fabian and L.M.Watson (Academic Press, New York 1973) p. 521
4. See, for example, H.Merz: Silicates Industriels, 1976–6, p. 285 (1973) and references contained therein
5. R.R.Turtle, R.J.Liefeld: Phys. Rev. B7, 3411 (1973)