RT Journal Article SR Electronic T1 Correction JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 816 OP 816 DO 10.1136/jcp.39.7.816-b VO 39 IS 7 YR 1986 UL http://jcp.bmj.com/content/39/7/816.2.abstract AB