Khan, Sakhawat Mahmud, et al. “Relationship of Various Prognostic Factors With Outcome of Treatment of Chronic Duodenal Ulcer Perforation Patients”. Chattagram Maa-O-Shishu Hospital Medical College Journal, vol. 13, no. 2, Nov. 2014, pp. 32-35, doi:10.3329/cmoshmcj.v13i2.21060.