RadzievskiiG. V. “Uniqueness of Solutions of Some Nonlocal Boundary-Value Problems for Operator-Differential Equations on a Finite Segment”. Ukrains’kyi Matematychnyi Zhurnal 55, no. 7 (July 25, 2003): 1006-1009. Accessed November 22, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/3976.