Mahmoud Mustafa B. The Effect of Ionic Substitution on the E.P. of Superconductor using Madelung Method. EDUSJ [Internet]. 2009 Mar. 1 [cited 2025 Aug. 6];22(1):78-92. Available from: https://ojs.uomosul.edu.iq/index.php/edusj/article/view/23973