A construction of an infinite dimensional invariant torus for a countable system of linear differential-difference equations via the method of reduction in the angular variable. Neliniini Kolyvannya, [S. l.], v. 14, n. 2, p. 267–280, 2011. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/606. Acesso em: 21 jan. 2026.