Manjit Singh,  Optimal ECG Sampling Frequency for Multiscale Entropy-Based HRV.   journal   = {International Journal of Biomedical and Biological Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2018, vol. 134(2). 26 - 30
    [viewed 27 January 2022]. Available from: https://publications.waset.org/pdf/10008566.