A positive solution of singular impulsive differential equations with nonlinear boundary conditions. Neliniini Kolyvannya, [S. l.], v. 17, n. 2, p. 200–212, 2014. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/739. Acesso em: 8 dec. 2025.