1. Brüll, L. and Lange, H. (1986 a). Stationary, Oscillatory and solitary wave type solutions of singular nonlinear Schrödinger equations. Math. Methods Appl. Sci. 8: 559–575.
2. Brüll, L. and Lange, H. (1986 b). Solitary waves for quasi-linear Schrödinger equations. Expos. Math. 4: 279–288.
3. Cazenave, T. (1986). Some remarks on the asymptotic behaviour of solutions to nonlinear Schrödinger equations. Preprint, Zentrum für interdisziplinäre Forschung, Universität Bielefeld.
4. Cazenave, T., Dias, J.P. and Figueira, M. (1982). A remark on the decay of the solutions of some Schrödinger equations. Rend. Sem. Mat. Univ. Politec. Torino 40: 129–137.
5. Dias, J.P. and Figueira, M. (1982). On the decay of the solution of some nonlinear Schrödinger equation. Portugalia Matematica 41: 33–41.