1. A.R. Lang (1974) Proc. Roy. Soc. Lond A 340 233
2. A.R. Lang (1977) J. Crystal Growth 42 625
3. A.R. Lang (1970) in Modern Diffraction and Imaging Techniques in Material Science (ed. S. Amelinckx, R. Gevers, G. Remaut and J. Van Landuyt) N. Holland p. 407
4. B.K. Tanner (1976) X-ray Diffraction Topography, Pergamon Press
5. R. Argemi, C. G’Sell and B. Baudelet (1971) Rev. Sci. Inst. 42 1711