TY - JOUR T1 - Reply JF - Thorax JO - Thorax SP - 218 LP - 218 DO - 10.1136/thx.43.3.218-a VL - 43 IS - 3 AU - PJM GEORGE AU - MR Hetzel AU - FJC MILLARD Y1 - 1988/03/01 UR - http://thorax.bmj.com/content/43/3/218.2.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -