M. I. Díaz-Benítez, A. L. Masi, C. Adorno, and I. Prieto, “Endoscopic characterization of patients with upper gastrointestinal bleeding in the digestive endoscopy department, Hospital Nacional de Itauguá, period 2020”, Cir. parag., vol. 45, no. 2, pp. 08–12, Sep. 2021.