AKYMENKO, A. M.; YAKOVETS, V. P. On Periodic Solutions of Degenerate Singularly Perturbed Linear Systems with Multiple Elementary Divisor. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 54, n. 10, p. 1403–1415, 2002. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4178. Acesso em: 7 apr. 2025.