Abstract
References
1.
Allison
V. D.
(1946 ) Brit. med. J. (i ), 673 .
2.Med. Res. Counc. (1948 ) Report No. 262. Studies in Air Hygiene.
3.
Watkins
A. G.
Lewis-Faning
E.
(1949 ) Brit. med. J. (ii ), 616 .