1. J. Weertman and J. R. Weertman, ?Physical Metallurgy?, edited by R. W. Cahn (North-Holland, Amsterdam, 1965) p. 793.
2. J. Weertman, Trans. Amer. Soc. Metals 61 (1968) 681.
3. M. F. Ashby, Acta Met. 20 (1972) 887.
4. R. L. Stocker and M. F. Ashby, Rev. Geophys. Space Phys. 11 (1973) 391.
5. M. F. Ashby, ?The Microstructure and Design of Alloys?, Vol. 2 (The Institute of Metals and The Iron and Steel Institute, London, 1973) p. 8.