WASET
    S. J. Arif,  A Simple and Efficient Method for Accurate Measurement and Control of Power Frequency Deviation.   journal   = {International Journal of Electronics and Communication Engineering}, [online]. World Academy of Science, Engineering and Technology.
    April 2016, vol. 114(6). 761 - 766
    [viewed 19 April 2024]. Available from: https://publications.waset.org/pdf/10004718.