Nonlinear integro-differential boundary-value problems unsolvable with respect to the derivative. Neliniini Kolyvannya, [S. l.], v. 24, n. 2, p. 278–288, 2021. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/1030. Acesso em: 21 jan. 2026.