Kaplun, Y.I., Samoilenko, A.M. and Samoilenko, V.G. (2002) “Singularly Perturbed Equations with Impulse Action”, Ukrains’kyi Matematychnyi Zhurnal, 54(8), pp. 1089–1009. Available at: https://umj.imath.kiev.ua/index.php/umj/article/view/4149 (Accessed: 6 December 2025).