Gonzalez Gonzalez R, Jacob J, Miro O, Llorens P, et al. Incidence, Clinical Characteristics, Risk Factors, and Outcomes of Upper
Gastrointestinal Bleeding in Patients With COVID-19: Results of the UMC-19-S12. J Clin Gastroenterol 2020 Nov 25. doi: 10.1097/MCG.0000000000001465.
PMID: 33252555