1. D. S. Billington and J. H. Crawford Jr, ?Radiation damages in solids? (Princeton University Press, Princeton, 1961).
2. E. Lell, N. J. Kreidl and J. R. Hensler, ?Progress in Ceramic Sciences?, (Pergamon Press, Oxford, 1966) Vol. 4, p. 1.
3. R. A. Weeks, ?Interaction of Radiation with Solids?, edited by A. Bishay (Plenum Press, New York, 1967) p. 55.
4. A. Treinen, ?Radical Ions?, edited by E. T. Kaiser and L. Kevan (Interscience, New York, 1968) Ch. 12.
5. A. Bishay, J. Non-Cryst. Solids 3 (1970) 54.