Averaging in a boundary-value problem for a multifrequency system with a drift in the argument. Neliniini Kolyvannya, [S. l.], v. 10, n. 4, p. 519–527, 2007. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/454. Acesso em: 10 dec. 2025.