S. Z. Sayed Hassen,  A Robust Approach to the Load Frequency Control Problem with Speed Regulation Uncertainty.   journal   = {International Journal of Electrical and Computer Engineering}, [online]. World Academy of Science, Engineering and Technology.
    August 2012, vol. 68(8). 826 - 833
    [viewed 21 May 2022]. Available from: https://publications.waset.org/pdf/4219.