Butt, Ahsan Masood, Ahmed Khan Chaudhry, M Awais Mughal, Taukeer Nasir ., Javaria Bint Zafar, and Khawar Rehman . “FREQUENCY OF DUODENAL ULCER PERFORATION WITH RADIOLOGICAL EVIDENCE OF PNEUMOPERITONEUM”. Pakistan Armed Forces Medical Journal 61, no. 2 (June 30, 2011): 211–3. Accessed May 30, 2025. https://www.pafmj.org/PAFMJ/article/view/284.