TY - JOUR T1 - Commentary JF - Thorax JO - Thorax SP - 317 LP - 318 DO - 10.1136/thx.50.3.317 VL - 50 IS - 3 AU - S Shaunak Y1 - 1995/03/01 UR - http://thorax.bmj.com/content/50/3/317.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -