Dil’naN. Z., and RontoA. M. “General Conditions for the Unique Solvability of Initial-Value Problem for Nonlinear Functional Differential Equations”. Ukrains’kyi Matematychnyi Zhurnal 60, no. 2 (February 25, 2008): 167–172. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3146.