“Environmental Duodenitis and Gastritis, Distribution of Campylobacter Piloris and Relationship With Intragastric PH and Nitrite”. Colombia Medica 20, no. 4 (December 31, 1989): 135–141. Accessed January 12, 2026. https://colombiamedica.univalle.edu.co/index.php/comedica/article/view/6268.