KomlevaT. A., PlotnikovA. V., and SkripnikN. V. “Differential Equations With Set-Valued Solutions”. Ukrains’kyi Matematychnyi Zhurnal, Vol. 60, no. 10, Oct. 2008, pp. 1326–1337, https://umj.imath.kiev.ua/index.php/umj/article/view/3247.