IVANYUK, N. N. Integration of a class of systems of differential equations by using a contour integral. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 47, n. 1, p. 30–38, 1995. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5379. Acesso em: 17 apr. 2025.