1. E. Schmid and W. Boas:Plasticity of Crystals, pp. 169–175, Chapman and Hall, London, reissued 1968.
2. A. Deruyttere and G. B. Greenough:J. Inst. Met., 1956, vol. 84, p. 337.
3. A. E. Deruyttere and G. B. Greenough:Nature, 1953, vol. 172, p. 170.
4. G. W. Greenwood and A. G. Quarrell:J. Inst. Met., 1954, vol. 82, p. 551.
5. J. J. Gilman:Trans. Am. Inst. Min. Metall. Pet. Eng., 1956, vol. 212, p. 783.