Kurniawan, E., and E. . Danardono. “Clinical Presentation and Outcome of Perforated Peptic Ulcer Patients at Dr. Soetomo Hospital Surabaya, Indonesia”. Bali Medical Journal, vol. 12, no. 3, Aug. 2023, pp. 2578-81, doi:10.15562/bmj.v12i3.4745.