1. C. S. Venable and W. G. Stuck: 'Internal fixation of fractures', 3; 1947, Springfield, Ill., C. C. Thomas.
2. H. E. Sigerist: 'A history of medicine', 111; 1961, New York, McGraw-Hill.
3. C. O. Bechtol et al. 'Metals and engineering in bone and joint surgery', 8; 1959, Baltimore, Williams and Wilkins.
4. H. Yamada: 'Strength of biological materials', (ed. F. G. Evans), 19; 1970, Baltimore, Wil-liams and Wilkins.
5. R. B. Duthie and A. B. Ferguson, Jr: 'Mercer's orthopaedic surgery', 1159; 1973, London, E. Arnold.