“…the more recent ones [24], [29], [30], [28] with their references). From mathematical viewpoint, the existence of vortices for the nonlinear Klein-Gordon equations (NKG), for nonlinear Schroedinger equations (NSE) and for nonlinear Klein-Gordon-Maxwell equations (NKGM) has been studied in some recent papers ( [18], [2], [3], [10], [16], [7], [8], [15]).…”