N.V.RAMANA, L. R. Robust Utkin’s Observer Based Controller for Deregulated Hydro-Thermal LFC Problem. International Journal of Engineering and Computer Science, india, v. 4, n. 08, 2015. Disponível em: http://ijecs.in/index.php/ijecs/article/view/3375. Acesso em: 5 may. 2024.