1. R.H.Bube: Photoconductivity of Solids (Wiley, New York 1960) Chap. 9
2. P.Bräunlich: “Thermoluminescence and Thermally Stimulated Conductivity”, in Thermoluminescence of Geological Materials, ed. by D.J.McDougall (Academic Press, New York 1968 ) pp. 61–90
3. A.G.Milnes: Deep Impurities in Semiconductors (Wiley-Interscience, New York 1973) Chap. 9
4. G. F.J.Garlick: Luminescence, in Handbuch der Physik, Vol. 26, ed. by S.Flügge (Springer, Berlin, Göttingen, Heidelberg 1958 ) pp. 1–128
5. D.Curie: Luminescence in Crystals (Wiley, New York 1963) Chap. 6