PlotnikovV. A. “Quasidifferential Equations in Semilinear Metric Spaces”. Ukrains’kyi Matematychnyi Zhurnal 50, no. 1 (January 25, 1998): 148–153. Accessed July 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/4980.