Keskin, B. and Ozkan, S.A. (2012) “Spectral problem for discontinuous integro-differential operator”, Ukrains’kyi Matematychnyi Zhurnal, 64(2), pp. 277–282. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/2575 (Accessed: 5 December 2025).