University Potsdam, Nonlinear Dynamics Group, Germany. steuer@agnld.uni-potsdam.de|University Potsdam, Nonlinear Dynamics Group, Germany. steuer@agnld.uni-potsdam.de|University Potsdam, Nonlinear Dynamics Group, Germany. steuer@agnld.uni-potsdam.de|University Potsdam, Nonlinear Dynamics Group, Germany. steuer@agnld.uni-potsdam.de|University Potsdam, Nonlinear Dynamics Group, Germany. steuer@agnld.uni-potsdam.de