M. Boulakroune and  M. Challal and  H. Louazene and  S. Fentiz,  Design and Synthesis of Two Tunable Bandpass Filters Based On Varactors and Defected Ground Structure.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    February 2015, vol. 99(3). 320 - 324
    [viewed 24 April 2024]. Available from: https://publications.waset.org/pdf/10000735.