Existence of Solutions for a Class of Quasilinear Elliptic Systems with Indefinite Weights. Journal of Partial Differential Equations, [S. l.], v. 18, n. 3, p. 219–226, 2005. Disponível em: https://global-sci.com/index.php/jpde/article/view/4046. Acesso em: 6 dec. 2025.