Fahim, Muhammad, Muhammad Sohail, Muhammad Sajjad Khan, Fahim Ullah Khan, Salman Ur Rashid, and Shakeel Akhter. “Frequency of Bleeding Duodenal Ulcer in Patients Presenting With Upper Gastrointestinal Bleeding: Frequency of Duodenal Ulcer in Patients With Gastrointestinal Bleeding”. Pakistan Journal of Health Sciences 3, no. 06 (November 30, 2022): 88–92. Accessed May 19, 2024. https://thejas.com.pk/index.php/pjhs/article/view/308.