Amaral, Maria J., Marco Serôdio, Emília C. Fraga, Cristina P. Camacho, Ana C. Almeida, António Manso, and José G. Tralhão. 2020. “Perforated Duodenal Ulcer After Gastric Bypass: A Challenging Diagnosis”. International Surgery Journal 7 (2):573-75. https://doi.org/10.18203/2349-2902.isj20200314.