Xin-Lei Feng and  Ting-Zhu Huang,  Some Results of Sign patterns Allowing Simultaneous Unitary Diagonalizability.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    August 2011, vol. 56(8). 1252 - 1254
    [viewed 19 April 2021]. Available from: https://publications.waset.org/pdf/4177.