1. Adie, G. C., Childress, W. G., Brezing, H. J., and Taylor, D. (1952). J. thorac. Surg., 23, 92.
2. Baffes, T. G., Schlotterbeck, P., and De Camp, P. T. (1954). Ibid., 27, 349.
3. Beaconsfield, P., Coulthard, H. S., and Kergin, F. G. (1954). Thorax, 9, 211.
4. Indian mned;Dingley, H.B.;Gaz,1950
5. Douglass, R.,and Bosworth, E. B. (1954). Amer. Rev.Tuberc.,69, 930.