Sieger, J. S. (1975). 1 Non-Cryst. Solids 19, 213-220.
Colombin, L., Jelli, A., Riga. J., Pireaux, J. J. & Verbist, J. (1977). J. Non-Cryst. Solids 24, 253.
Lie, L., & Chao, X. (1990). J. Non-Cryst. Solids 119, 37.
Principi, G., Maddalena, A. & Gupta, A. (1993). Nuclear. Instr. and Methods in Phys. Research B
76, 215.
Pantano, C. O., Bojan, V., Yenta, M., Geotti-Bianchini, F. & Hregliich, S. (1993). Rivista della
Stazione Sperimentale del Vetro Vol. XX111, 285.
Karim, M. & Holland, D. (1995). Glastech. Ber. Glass Sci. Technol. 68 Cl.
Holland, D., Karim, M. M., Johnson, C. E., Williams, K. & Johnson, J. A. (1993) Proc. “2nd
International Conference, European Society of Glass (Venice), Rivistadella Stanzione
Sperimentale del Vetro 23, 223.
Johnson, J. A., Johnson, C. E., Williams. K., Holland, D. & Karim, M. (1995). Hyperfine Interactions
95, 41-45.