RT Journal Article SR Electronic T1 ABO Blood Groups and Gastric Ulcer JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 24 OP 25 DO 10.1136/jmg.2.1.24 VO 2 IS 1 A1 Macafee, A. L. YR 1965 UL http://jmg.bmj.com/content/2/1/24.abstract AB