Existence of solutions for a class of fourth-order multi-point boundary value problems on time scales. Neliniini Kolyvannya, [S. l.], v. 16, n. 3, p. 336–349, 2013. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/702. Acesso em: 10 mar. 2026.