WASET
    A. Fayad and  Q. Alqhazaly and  T. Cinkler,  Time and Wavelength Division Multiplexing Passive Optical Network Comparative Analysis: Modulation Formats and Channel Spacings.   journal   = {International Journal of Electronics and Communication Engineering}, [online]. World Academy of Science, Engineering and Technology.
    May 2021, vol. 174(6). 231 - 237
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/10012070.