Saber Eltohamy, M., M. Said Abdel Moteleb, H. Talaat, S. Fouad Mekhemer, and W. Omran. “Power System Flexibility Metrics Review With High Penetration of Variable Renewable Generation”. Information Technology Applications, vol. 8, no. 1, Sept. 2023, pp. 21-46, https://www.itajournal.com/index.php/ita/article/view/58.