1. Verma, “Crystal Growth and Dislocations” (Butterworths Scientific Publications, London, 1953).
2. Voltava and Amelinckx, Naturwiss. (1954).
3. Dekeyser, Conf. on Defects in Crystalline Solids, Bristol (July 1954). Gilman, and Johnston, J. App. Phys., 27, 1018 (1956).