Maham Abdaal, Numan Ghafoor, Isma Akram, Muhammad Usman, Saqib Hussain, Mehdi Naqvi. “Endoscopic Determination of Various Causes of Upper Gastrointestinal Bleeding”. Pakistan Journal of Medical & Health Sciences, vol. 16, no. 12, Jan. 2023, p. 183, doi:10.53350/pjmhs20221612183.