1. D. Beney and G. Roskes, Wave instability, Studies in Applied Math 48 (1969), 455–472.
2. Instabilité des états stationnaires dans les équations de Schrödinger et de Klein-Gordon non linéaires;Berestycki, Henri;C. R. Acad. Sci. Paris S\'{e}r. I Math.,1981
3. Orbital stability of standing waves for some nonlinear Schrödinger equations;Cazenave, T.;Comm. Math. Phys.,1982
4. On the existence of standing waves for a Davey-Stewartson system;Cipolatti, Rolci;Comm. Partial Differential Equations,1992
5. On the instability of ground states for a Davey-Stewartson system;Cipolatti, Rolci;Ann. Inst. H. Poincar\'{e} Phys. Th\'{e}or.,1993