MeszarosJ., and RontoM. I. “Some Remarks Concerning the Convergence of the Numerical-Analytic Method of Successive Approximations”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 48, no. 1, Jan. 1996, pp. 90-95, https://umj.imath.kiev.ua/index.php/umj/article/view/5366.