KENZHEBAEV, K. K.; LAPTINSKII, V. N. Analytic representation of periodic solutions of linear differential systems. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 5, p. 731–735, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5057. Acesso em: 5 dec. 2025.