PT - JOURNAL ARTICLE ED - , TI - CORRECTION AID - 10.1136/thx.49.1.96-a DP - 1994 Jan 01 TA - Thorax PG - 96--96 VI - 49 IP - 1 4099 - http://thorax.bmj.com/content/49/1/96.2.short 4100 - http://thorax.bmj.com/content/49/1/96.2.full SO - Thorax1994 Jan 01; 49