PROUDNIKOV, L. M. Construction of a stabilizing control and solution to a problem about the center and the focus for differential systems with a polynomial part on the right side. CUBO, A Mathematical Journal, [S. l.], v. 9, n. 3, p. 13–28, 2007. Disponível em: https://cubo.ufro.cl/index.php/cubo/article/view/1584. Acesso em: 12 oct. 2025.