1. J. H. Schulman and W. D. Compton, Color Centers in Solids, Pergamon, New York (1962).
2. J. J. Markham, F-Centers in Alkali Halides, Academic, New York (1966).
3. W. B. Fowler (ed.), Physics of Color Centers, Academic, New York (1968).
4. J. H. Crawford, Jr. and L. M. Slifkin (eds.), Point Defects in Solids, Vol. 1. General and Ionic Crystals, Plenum, New York (1972).
5. 1971 Int. Conf. on Colour Centers in Ionic Crystals, Reading, England (1971).