Periodic solutions for a system of linear nonhomogeneous first order differen- tial equations with rectangular periodic matrices. Neliniini Kolyvannya, [S. l.], v. 18, n. 1, p. 38–54, 2015. Disponível em: https://twinhead.imath.kiev.ua/index.php/nosc/article/view/768. Acesso em: 21 jan. 2026.