Hanan K. Abdulkrim, Nawroz I. Hamadamen, Salar J. Abdulhameed,. “Production Survey of Designing a Hybrid Optical Amplifier (HOP) for WDM Systems by Using EDFA and RAMAN Amplifiers”. Design Engineering (August 7, 2021): 7476-7491. Accessed May 2, 2024. http://thedesignengineering.com/index.php/DE/article/view/3257.