Quasiperiodic solutions of functional-singularly perturbed linear ordinary higher-order differential equations. Neliniini Kolyvannya, [S. l.], v. 21, n. 4, p. 457–469, 2018. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/922. Acesso em: 21 jan. 2026.