The second issue of 2016 of Ricerche di Matematica and the first one of 2017 are Special Issues devoted to Waves and Stability. I thank the contribution of all the Authors and stress that a large spectrum of research fields has been investigated by them. The aim of these Special Issues is to try to contribute significantly to the modern international literature on Waves and Stability.

Prof. Salvatore Rionero

Editor in Chief    

Ricerche di Matematica