M. Naddaf and A. M. Anbaran, “Gain Flattening Improvements With Two Cascade Erbium Doped Fiber Amplifier In WDM Systems”, IAJSE, vol. 3, no. 1, pp. 143–149, Jun. 2016, Accessed: Sep. 23, 2026. [Online]. Available: https://iaiest.com/iaj/index.php/IAJSE/article/view/IAJSE1510014