1. Berglund, E., Birath, G., Bjure, J., Grimby, G., Kjellmer, J., Sandqvist, L., and Soderholm, B. (1963). Acta med. scand., 173, 185.
2. Bernstein, L., d'Silva, J. L., and Mendel, D. (1952). Thorax, 7, 255. Ciba Guest Symposium (1959). Ibid., 14, 286.
3. Drutel, P., and Dechoux, J. (1952). J. franC. Med. chir. thor., 6, 517.
4. In Bronchitis, An International Symposium, 1960, Groningen;Fletcher, C.M.,1961
5. Fowler, W. S. (1952). Physiol. Rev., 32, 1.