TY - JOUR T1 - AUTHOR'S REPLY JF - Thorax JO - Thorax SP - 983 LP - 983 DO - 10.1136/thx.45.12.983-a VL - 45 IS - 12 AU - Huon H Gray AU - John M Morgan Y1 - 1990/12/01 UR - http://thorax.bmj.com/content/45/12/983.2.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -