SKÓRA, L. Boundary value problem for the second order impulsive delay differential equations. Annales Universitatis Paedagogicae Cracoviensis Studia Mathematica, [S. l.], v. 14, p. 27–35, 2015. Disponível em: https://studmath.uken.krakow.pl/article/view/13151. Acesso em: 31 oct. 2026.