SoldatovV. O. “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, Vol. 67, no. 5, May 2015, pp. 692–700, https://umj.imath.kiev.ua/index.php/umj/article/view/2015.