“…Some authors have studied different aspects of the problem of stabilization for a fixed time delay (see [3,5,14,20,23,29,31,34,35,37,39,41,44,[46][47][48][49]) while some others have considered the problem of stabilization independent of delays [4,5,7,[9][10][11]13,[26][27][28]30,33,45]. On the other hand, some of these works are concentrated on the design of asymptotic observers with point delays (commensurate or noncommensurate) while some others consider distributed delays.…”