Wang , Yan and Zhao , Xiaofei. (2018). Symmetric High Order Gautschi-Type Exponential Wave Integrators Pseudospectral Method for the Nonlinear Klein-Gordon Equation in the Nonrelativistic Limit Regime.
            <i>International Journal of Numerical Analysis and Modeling</i>. <i>15</i> (3).
            405-427.
         doi: