1. G. Mahler, V. May, M. Schreiber (Eds.), Molecular Electronics, Properties, Dynamics and Applications, Marcel Dekker, New York, 1996, p. 385.
2. R.L. Cone, Y. Sun, F. Könz, N.M. Strickland, T.L. Harris, C.W. Thiel, T. Böttger, G. Reinemer, W.R. Babbitt, R.W. Equall, R.L. Hutcheson, R.M. Macfarlane, J.A. Ritcey, New Rare Earth Materials, Material Concepts and Demonstrations of Spectral Hole Burning Applications, Book of Abstracts HBRS'99, sixth International Meeting on Hole Burning and Related Spectroscopies, Science and Applications, September 18–23, Hourtin, France, p. 6.
3. Impurity Spectra of Solids;Rebane,1970