Umar Alhaji Mukhtar and  Abubakar Mohammed El-jummah,  Piezoelectric Power Output Predictions Using Single-Phase Flow to Power Flow Meters.   journal   = {International Journal of Energy and Power Engineering}, [online]. World Academy of Science, Engineering and Technology.
    September 2019, vol. 154(10). 657 - 662
    [viewed 19 November 2019]. Available from: https://publications.waset.org/pdf/10010814.