A.C. Propper, J.N. Carter, R.D.T. Lauder, D.C. Hanna, S.T. Davey, D. Szebesta. J. Opt. Soc. Amer. B; Opt. Phys., 11, 886 (1994)
W.S. Brocklesby, A. Pearson. J. Luminesc., 59, 333 (1994)
D.W. Hewak, R.S. Deol, J. Wang, G. Wylangowski, J.A. Mederios Neto, B.N. Samson, R.I. Laming, W.S. Brocklesby, D.N. Payne, A. Jha, M. Poulain, S. Otero, S. Surinach, M.D. Baro. Electron. Lett., 29, 237 (1993)
D.R. Simons, A.J. Faber, H. De Waal. Proc. 8th Int. Symp. on Halide Glasses, Perros-Guirrec, France 1992 (CNET, Lannion, France 1992) p. 448
B. Frumarova, J. Oswald, P. Krecmer, M. Frumar, V. Cerny, V. Smrcka. Opt. Mater., 6, 217 (1996)
B. Frumarova, M. Frumar, J. Oswald. J. Non-Cryst. Sol., 213--214, 58 (1997)
A. Belykh, L. Glebov, C. Lerminiaux, S. Sunter, M. Mikhailov, A. Pliukhin, M. Prassas, A. Przhevuskii. J. Non-Cryst. Sol., 213--214, 238 (1997)
R.S. Deol, D.W. Hewak, S. Jordery, A. Jha, M. Poulain, M.D. Baro, D.N. Payne. J. Non-Cryst. Sol., 161, 257 (1993)
H. Ebendorff-Heidepriem, W. Seeber, D. Ehrt. J. Non-Cryst. Sol., 183, 191 (1995)
P. Nachimuthu, R. Jaganathan. Phys. Chem. Glasses, 36, 194 (1995)
S.X. Cardoso, Y. Messaddeq, L.A.O. Nunes, M.A. Aegerter. J. Non-Cryst., Sol., 161, 277 (1993)
M. Horak, D. Papuusek. Infrared Spectra and Structure of Molecules (Academia, Praha 1976) p. 254 (in Czech)
M. Frumar, B. Petrova, V. Cerny, I. Pavlik. In: Advanced Solid State Chemisty, Materials Science Monographs, 60, ed. by M. Frumar, V. Cerny and L.Tichy (Elsevier, Amsterdam 1989) p. 401
L. Koudelka, M. Frumar, M. Pisarcik. J. Non-Cryst., Sol., 41, 171 (1980)
Z.V. Popovic. Phys. Lett., 94A, 2442 (1983)
B.R. Judd. Phys. Rev., 127, 750 (1962)
G.S. Ofelt. J. Chem. Phys., 37, 511 (1962)
A.T. Stanley, E.A. Harris, T.M. Searle, J.M. Parker. J. Non-Cryst. Sol., 161, 235 (1993)