On approximation of systems of neutral type of differential-difference equations with systems of ordinary differential equations. Neliniini Kolyvannya, [S. l.], v. 10, n. 3, p. 328–335, 2007. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/442. Acesso em: 21 jan. 2026.