1. D. S. Billington and J. H. Crawford, Jr., Radiation Damage in Solids, Princeton, N. J.: Princeton University Press, 1961.
2. L. T. Chadderton, Radiation Damage in Crystals, N. Y.; John Wiley, 1965; G. J. Dienes and G. H. Vineyard, RADIATION EFFECTS IN SOLIDS, N. Y.: Interscience Publ. 1957; and A. C. Damask and G. J. Dienes, POINT DEFECTS IN METALS, N. Y.: Gordon and Breach, 1963.
3. G. Czjzek. and W. G. Berger, Phys. Rev. B1, 957 (1970).
4. C. G. Jacobs, Jr., N. Hershkowitz, and J. B. Jeffries, Phys. Letters 29A, 498 (1969).
5. G. Czjzek, J. L. C. Ford, Jr., J. C. Love, F. E. Oben-shain, and H. H. F. Wegener, Phys. Rev. 174, 331 (1968).