ROMANYSHYN, I. M.; SYNYTS’KYI, L. A. Construction of approximations for a stationary solution of a system of singular ordinary differential equations. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 49, n. 6, p. 774–778, 1997. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5061. Acesso em: 5 dec. 2025.