WASET
    R. Borghol and  T. Aguili,  Discrimination of Modes of Double- and Single-Negative Grounded Slab.   journal   = {International Journal of Electronics and Communication Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2017, vol. 125(5). 564 - 568
    [viewed 27 April 2024]. Available from: https://publications.waset.org/pdf/10007099.