On existence of solution and averaging for multipoint boundary-value problems for many-frequency systems with linearly transformed argument. Neliniini Kolyvannya, [S. l.], v. 11, n. 4, p. 462–471, 2008. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/492. Acesso em: 21 jan. 2026.