M. Mohammad, Huda, هدى, Nawfal Y. Jamil, نوفل, Abdulghafoor I. Abdullah, and عبد. “Dispersion Properties of Up-Doping Photonic Crystal Fibers”. Rafidain Journal of Science 25, no. 1 (June 24, 2025): 101–107. Accessed August 14, 2025. https://ojs.uomosul.edu.iq/index.php/rsci/article/view/12286.