1. E. Orowan, in “Reports of Progress in Physics”, Physical Society: London, vol. 12, p. 185 (1949).
2. G. M. Whitesides, in this volume.
3. D. G. Pettifor, in this volume.
4. E. Esposito, A. E. Carlsson, D. D. Ling, H. Ehrenreich, and C. D. Gelatt, Jr., Phil. Mag., 41, 251 (1980).
5. N. H. Macmillan, in this volume.