Helicobacter pylori Infection in European children with gastro-duodenal ulcers and erosions., Bontems, Patrick, Kalach Nicolas, Vanderpas Jean, Iwanczak Barbara, Casswall Thomas, Koletzko Sibylle, Oderda Giuseppina, Martinez-Gomez Maria José, Urruzuno Pedro, Kindermann Angelika, et al. , Pediatr Infect Dis J, 2013 Dec, Volume 32, Issue 12, p.1324-9, (2013)