A construction of periodic solutions for linear partial differential systems with linear deviations in the argument. Neliniini Kolyvannya, [S. l.], v. 7, n. 4, p. 462–467, 2004. Disponível em: https://nosc.imath.kiev.ua/index.php/nosc/article/view/322. Acesso em: 12 apr. 2026.