PT - JOURNAL ARTICLE AU - BJ Lipworth TI - AUTHOR'S REPLY AID - 10.1136/thx.48.7.776-a DP - 1993 Jul 01 TA - Thorax PG - 776--776 VI - 48 IP - 7 4099 - http://thorax.bmj.com/content/48/7/776.2.short 4100 - http://thorax.bmj.com/content/48/7/776.2.full SO - Thorax1993 Jul 01; 48