1. Random Dynamical Systems;Arnold,1998
2. Forced quasiperiodic and almost periodic oscillations of nonlinear Duffing equations;Berger;Nonlinear Anal.,1992
3. New method for large quasiperiodic nonlinear oscillations with fixed frequencies for the nondissipative forced Duffing equation (I);Berger;Panamer. Math. J.,1994
4. New method for large quasiperiodic nonlinear oscillations with fixed frequencies for the nondissipative second type Duffing equation;Berger;Topol. Methods Nonlinear Anal.,1995
5. Quasiperiodic solutions of saddle point type for the Duffing equations with small forcing;Berger;Comm. Appl. Nonlinear Anal.,1997