Atlasiuk, O. M., and V. A. Mikhailets. 2018. “Fredholm One-Dimensional Boundary-Value Problems with parameter in Sobolev Spaces”. Ukrains’kyi Matematychnyi Zhurnal 70 (11), 1457-65. https://umj.imath.kiev.ua/index.php/umj/article/view/1649.