Mikhailets, V. A., A. A. Murach, and V. Soldatov. 2016. “A Criterion for Continuity in a Parameter of Solutions to Generic Boundary-Value Problems for Higher-Order Differential Systems”. Methods of Functional Analysis and Topology 22 (4): 375-86. https://zen.imath.kiev.ua/index.php/mfat/article/view/647.