RT Journal Article SR Electronic T1 an introduction to human blood groups JF Journal of Clinical Pathology JO J Clin Pathol FD BMJ Publishing Group Ltd and Association of Clinical Pathologists SP 217 OP 217 DO 10.1136/jcp.14.2.217-d VO 14 IS 2 A1 R. H. B. Protheroe YR 1961 UL http://jcp.bmj.com/content/14/2/217.4.abstract AB