“…Last but not least, we recall some results concerning the exponential or polynomial indirect stability of systems which arise from physical problems. For example, we quote [1,9,20,22,28,34,40,41] for the Bresse system and [2,7,12,14,25,33,36] for the Timoshenko system. The Bresse system is usually considered in the study of elastic structures of the arcs type (see [26]) while the Timoshenko system is usually considered in describing the transverse vibration of a beam and it ignores damping effects of any nature (see [39]).…”