RizkM. M., and ZaherS. L. 1997. “On the Approximate Solution of Nonlinear Volterra-Fredholm Integral Equations on a Complex Domain by Dzyadyk’s Method”. Ukrains’kyi Matematychnyi Zhurnal 49 (11), 1519–1528. https://umj.imath.kiev.ua/index.php/umj/article/view/5151.