1. ASM Symposium, “Atom Movements,” American Society for Metals, Cleveland, 1951.
2. R. M. BARRER, “Diffusion in and through Solids,” Cambridge U. P. New York, 1951.
3. W. HUME-ROTHERY, “Atomic Theory for Students of Metallurgy,” p. 216, Inst. of Metals, London, 1948.