1. Stevels JM (1957) The electrical properties of glass. In: Flügge S (ed) Handbuch der Physik. Springer, Berlin Heidelberg New York, p 350
2. Macedo PB, Moynihan CT, Bose RA (1972) Phys Chem Glasses 13:171
3. Pollak M, Pike GE (1972) Phys Rev Lett 28:1449
4. Jonscher AK (1977) Nature 267:673
5. Mott NF, Davis EA (1979) Electronic processes in non-crystalline materials. Clarendon Press, Oxford