RT Journal Article SR Electronic T1 Postgraduate Haematology JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 1315 OP 1316 DO 10.1136/jcp.42.12.1315-e VO 42 IS 12 A1 Winfield, DA YR 1989 UL http://jcp.bmj.com/content/42/12/1315.5.abstract AB