Existence of solutions to a boundary-value problem for nonlinear fractional order differential equation. Neliniini Kolyvannya, [S. l.], v. 19, n. 2, p. 161–172, 2016. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/820. Acesso em: 21 jan. 2026.