RontoM. I., SamoilenkoA. M., and TrofimchukS. I. “The Theory of the Numerical-Analytic Method: Achievements and New Trends of Development. VI”. Ukrains’kyi Matematychnyi Zhurnal 51, no. 7 (July 25, 1999): 960–971. Accessed September 1, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4685.