title: ABO blood groups in duodenal ulcer, gastric ulcer and the pseudo-ulcer syndrome.
mesh_terms: D000017:ABO Blood-Group System; D003718:Denmark; D004381:Duodenal Ulcer / Q000453:epidemiology*; D006801:Humans; D010438:Peptic Ulcer Hemorrhage / Q000453:epidemiology; D010439:Peptic Ulcer Perforation / Q000453:epidemiology; D013276:Stomach Ulcer / Q000453:epidemiology*
chemical_list: D000017:ABO Blood-Group System