1. W. Boas andR. W. K. Honeycombe,Proc. Roy. Soc. 186A (1946) 57.
2. Idem, ibid 188A (1946/47) 427.
3. Idem, J. Inst. Metals 73 (1946/47) 433.
4. G. A. Malygin andV. A. Likhachev,Zavodskaya Laboratoriya 32 (3) (1966) 335.
5. V. A. Likhachev,Sov. Phys. Solid State 3 (1961) 1330.