Zhenyu Zhao and  Lei You,  Fourier Spectral Method for Analytic Continuation.   journal   = {International Journal of Mathematical and Computational Sciences}, [online]. World Academy of Science, Engineering and Technology.
    March 2011, vol. 51(3). 374 - 376
    [viewed 15 January 2021]. Available from: https://publications.waset.org/pdf/9760.