PT - JOURNAL ARTICLE ED - , TI - Proceedings of the Thoracic Society AID - 10.1136/thx.26.2.229 DP - 1971 Mar 01 TA - Thorax PG - 229--232 VI - 26 IP - 2 4099 - http://thorax.bmj.com/content/26/2/229.short 4100 - http://thorax.bmj.com/content/26/2/229.full SO - Thorax1971 Mar 01; 26