Liming Zhang,  A Novel Instantaneous Frequency Computation Approach for Empirical Mode Decomposition.   journal   = {International Journal of Electronics and Communication Engineering}, [online]. World Academy of Science, Engineering and Technology.
    December 2012, vol. 72(12). 1524 - 1528
    [viewed 30 March 2020]. Available from: https://publications.waset.org/pdf/14372.