Seifouri, M., M. M. Karkhanehchi, and S. Rohani. “Design of Multi-Layer Optical Fibers With Ring Refractive Index to Reduce Dispersion and Increase Bandwidth in Broadband Optical Networks”. Engineering, Technology & Applied Science Research, vol. 2, no. 3, June 2012, pp. 216-20, doi:10.48084/etasr.166.