Tomáš Urbanec,  Novel Approach for Wideband VNA by Sixport Principle.   journal   = {International Journal of Computer and Information Engineering}, [online]. World Academy of Science, Engineering and Technology.
    July 2007, vol. 7(7). 1881 - 1884
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/3574.