Bilal, M. Y., S. A. Ahmed, N. Riaz, I. Ullah, M. A. Hashmi, M. Ashiq, M. R. Kiani, and M. Yusuf. “Perforated Peptic Ulcer After Coronary Bypass Grafting, Two Case Reports”. Pakistan Heart Journal, vol. 26, no. 1-2, Aug. 2012, doi:10.47144/phj.v26i1-2.238.