1. Berestycki, H., Cazenave, T.: Instabilité des états stationnaires dans les équations de Schrödinger et de Klein-Gordon non linéaires. C.R. Acad. Sci. Paris Sér. I Math. 293, 489–492 (1981)
2. Berestycki, H., Gallouët, T., Kavian, O.: Equations de champs scalaires euclidiens non linéaires dans le plan. C.R. Acad. Sci. Paris Sér. I Math. 297, 307–310 (1983)
3. Ball, J.M.: In: Grandall, M.G. (ed.) Finite Time Blow-up in Nonlinear Problems in Nonlinear Evolution Equations, pp. 189–205. Academic Press, New York (1978)
4. Bisognin, V., Cavalcanti, M.M., Domingos Cavalcanti, V.N., Soriano, J.: Uniform decay for the coupled Klein-Gordon-Schrödinger equations with locally distributed damping. Nonlinear Differ. Equ. Appl. 15, 91–113 (2008)
5. Progress in Nonlinear Differential Equations and Their Applications;D. Santo Del,1997