Study of Serum Ferritin, Zinc, and Copper Levels in Children With Helicobacter pylori Gastritis and the Effect of the Treatment. - Elsaadany E; Amin S; Abdel-Hafez M; El Amrousy D; Kasem S; Abd Elaziz D; Shawky D (Journal of pediatric gastroenterology and nutrition, 2022)