PT - JOURNAL ARTICLE ED - , TI - Addendum AID - 10.1136/oem.28.3.307 DP - 1971 Jul 01 TA - British Journal of Industrial Medicine PG - 307--307 VI - 28 IP - 3 4099 - http://oem.bmj.com/content/28/3/307.short 4100 - http://oem.bmj.com/content/28/3/307.full SO - Br J Ind Med1971 Jul 01; 28