RT Journal Article SR Electronic T1 Proceedings of the Association of Industrial Medical Officers JF British Journal of Industrial Medicine JO Br J Ind Med FD BMJ Publishing Group Ltd SP 276 OP 276 DO 10.1136/oem.3.4.276 VO 3 IS 4 YR 1946 UL http://oem.bmj.com/content/3/4/276.abstract AB