TY - JOUR T1 - AUTHORS' REPLY JF - Thorax JO - Thorax SP - 1050 LP - 1050 DO - 10.1136/thx.48.10.1050-a VL - 48 IS - 10 AU - M G Pearson AU - M R Partridge AU - B D W Harrison Y1 - 1993/10/01 UR - http://thorax.bmj.com/content/48/10/1050.2.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -