Sher, F.; Ullah, R. S.; Khan, J.; Mansoor, S. N.; Ahmed, N. FREQUENCY OF DIFFERENT CAUSES OF UPPER GASTROINTESTINAL BLEEDING USING ENDOSCOPIC PROCEDURE AT A TERTIARY CARE HOSPITAL: Causes of Upper Gastrointestinal Bleeding. Pak Armed Forces Med J 2014, 64 (3), 410-3.