“Extrapolation and A-Posteriori Error Estimators of Petrov-Galerkin Methods for Non-Linear Volterra Integro-Differential Equations”, JCM, vol. 19, no. 4, pp. 407–422, Aug. 2001, Accessed: Mar. 14, 2026. [Online]. Available: https://gsp.tricubic.dev/JCM/article/view/11443