Amir, M., S. Hafeez, M. Adrees, A. Nazir, and H. M. Ather. “Causes of Upper Gastrointestinal Bleeding on Endoscopy in Tertiary Care Hospital”. Annals of Punjab Medical College (APMC), Vol. 14, no. 3, Sept. 2020, pp. 263-7, doi:10.29054/apmc/2020.695.