Kayali, Stefano, et al. “Helicobacter Pylori, Transmission Routes and Recurrence of Infection: State of the Art”. Acta Biomedica Atenei Parmensis, vol. 89, no. 8-S, Dec. 2018, pp. 72-76, https://doi.org/10.23750/abm.v89i8-S.7947.