SoldatovV. O. 2015. “On the Continuity in a Parameter for the Solutions of Boundary-Value Problems Total With Respect to the Spaces $C^{(n+r)}[a, b]$”. Ukrains’kyi Matematychnyi Zhurnal 67 (5), 692–700. https://umj.imath.kiev.ua/index.php/umj/article/view/2015.