RT Journal Article SR Electronic T1 In this number JF Journal of Epidemiology and Community Health JO J Epidemiol Community Health FD BMJ Publishing Group Ltd SP 329 OP 329 DO 10.1136/jech.48.4.329 VO 48 IS 4 YR 1994 UL http://jech.bmj.com/content/48/4/329.1.abstract AB