KOLOMIYETS, V. G.; MITROPOLSKIY, Yu. A.; SAMOILENKO, A. M. The conference “Nonlinear problems of differential equations and mathematical physics. The second Bogolyubov readings”. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 46, n. 4, p. 471, 1994. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/5751. Acesso em: 15 dec. 2025.