1. J. Aveston, G. A. Cooper andA. Kelly, The properties of fibre composites: single and multiple fracture? Paper 2 Conference Proceedings (National Physical Laboratory Teddington, UK 1971) pp. 15?26.
2. J. Aveston andA. Kelly,J. Mater. Sci. 8 (1973) 352.
3. R. A. J. Sambell, D. H. Bowen andD. C. Phillips,ibid. 7 (1972) 663.
4. D. H. Bowen, D. C. Phillips, R. A. J. Sambell andA. Briggs,Soc. Mater. Sci. Jpn 5 (1972) 123.
5. H. Poritsky,Phys. 5 (1934) 406.