Jayme G. A. Barbedo and  Amauri Lopes,  Estimating Frequency, Amplitude and Phase of Two Sinusoids with Very Close Frequencies.   journal   = {International Journal of Electronics and Communication Engineering}, [online]. World Academy of Science, Engineering and Technology.
    November 2009, vol. 35(11). 2026 - 2033
    [viewed 26 January 2020]. Available from: https://publications.waset.org/pdf/4390.