A. M. Nazari and  B. Sepehrian and  M. Jabari,  The Inverse Eigenvalue Problem via Orthogonal Matrices.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    September 2010, vol. 45(9). 1241 - 1246
    [viewed 23 January 2020]. Available from: https://publications.waset.org/pdf/14588.