1. H. Conrad, NPL symposium ?The Relation Between the Structure and Mechanical Properties of Metals? (HMSO, 1963) p. 476.
2. Idem 16 (1964) 582.
3. A. Seeger in ?Dislocations and Mechanical Properties of Crystals?, edited by J. Fisher et al (Wiley, New York, 1957) p. 243.
4. F. Guiu and P. L. Pratt, Phys. Stat. Solidi. 6 (1964) 111.
5. G. A. Sargent, Acta Met, 13 (1965) 663.