Mott, N.F., Davis, E.A.: Electronic Processes in Non-Crystalline Materials, Oxford: Clarendon Press 1971
Elliott, R.J., Krumhansl, J.A., Leath, P.L.: Rev. Mod. Phys.46, 465 (1974)
Thouless, D.J.: Phys. Repts.13C, 93 (1974)
Economou, E.N., Cohen, M.H., Freed, K.F., Kirkpatrick, E.S.: In: J. Tauc, Amorphous and Liquid Semiconductors, p. 101. London: Plenum Press 1974
Anderson, P.W.: Phys. Rev.109, 1492 (1958)
Licciardello, D.C., Thouless, D.J.: Phys. Rev. Lett.35, 1475 (1975)
Edwards, J.T., Thouless, D.J.: J. Physics C5, 807 (1972)
Abram, R.A., Edwards, S.F.: J. Physics C5, 1183 (1972)
Anderson, P.W.: Proc. Nat. Acad. Sci. USA69, 1097 (1972)
Freed, K.F.: Phys. Rev. B5, 4802 (1972)
Last, B.J., Thouless, D.J.: J. Physics C7, 699 (1974)
Bell, R.J., Dean, P.: Disc. Faraday Soc.50, 55 (1970)
Mott, N.F.: Phil. Mag.17, 1259 (1968)
