The complex WKB method for nonlinear equations. Progress in physics; Bd. 16.

Maslov, Victor P. - The Complex WKB Method for Nonlinear Equations I: Linear The

Nonlinear Differential Equations and Dynamical Systems, Verhulst Springer 1996

Variational methods. Applications to nonlinear partial differential equations an

Modeling Nonlinear Dynamics from Equations and Data with Applications to Solids,

Numerical Methods for Unconstrained Optimization and Nonlinear Equations:Prentic

Stability of Runge-Kutta Methods for Stiff Nonlinear Differential Equations Cwi

The Solution of a Certain Nonlinear Riemann-Hilbert Problem With an Application