1. D.A. Anderson and W.E. Spear. Phil. Mag. 35 (1977) 1
2. K. Bohringer, H. Mannsperger and S. Kalbitzer. Nuci. Instr. and Meth. B7/8 (1985) 299
3. H. Richter and H. Breitling, Z.Natf. A13 (1958)988
4. S.C. Moss and J.F. Graczyk, Proc. 10th Int. Conf. on the Physics of Semiconductors, Cambridge 1970, eds. S.P. Keller, J.C. Hensel and F.Stern. p. 658. United States Atomic Energy Commission, Washington, D.C.
5. D.E. Polk, J. Non-Cryst. Solids 5 (1971) 365