TY - JOUR T1 - Anne Cockroft and Paul Griffiths reply JF - British Journal of Industrial Medicine JO - Br J Ind Med SP - 645 LP - 646 DO - 10.1136/oem.47.9.645-a VL - 47 IS - 9 A2 - , Y1 - 1990/09/01 UR - http://oem.bmj.com/content/47/9/645.2.abstract N2 - 300 Multiple ChoicesThis is a pdf-only article and there is no markup to show you.full-text.pdf ER -