title: Perforated peptic ulcer and the civil disturbances in Belfast 1967-74.
mesh_terms: D004381:Duodenal Ulcer / Q000150:complications; D006801:Humans; D009660:Northern Ireland; D010439:Peptic Ulcer Perforation / Q000453:epidemiology* / Q000209:etiology; D013276:Stomach Ulcer / Q000150:complications; D014754:Violence