1. Cochrane, A. L., Cox, J. G., and Jarman, T. F. (1952). Brit. med. J., 2, 843. -, -(1955). Ibid., 1, 371.
2. Cochrane, A. L., Cox, J. G., and Jarman, T. F., Davies, I., and Fletcher, C. M. (1951). British Journal of Industrial Medicine, 8, 244.
3. Fletcher, C. M., Gilson, J. C., and Hugh-Jones, P. (1951). Ibid., 8, 53.
4. Proc. 9th Int;Davies, I.; Fletcher, C.M.; Mann, K.J.; Stewart, A.;Congr. on industr. Med., London,1949
5. Fletcher, C. M. (1948). Brit. med. J., 1, 1015, 1065.