Yi , Lijun and Guo , Benqi. (2018). The $h$-$p$ Version of the Continuous Petrov-Galerkin Method for Nonlinear Volterra Functional Integro-Differential Equations with Vanishing Delays.
            <i>International Journal of Numerical Analysis and Modeling</i>. <i>15</i> (1-2).
            26-47.
         doi: