WANG, W.; YANG, Z. Nonnegative solutions of quasilinear elliptic problems with sublinear indefinite nonlinearity. CUBO, A Mathematical Journal, [S. l.], v. 15, n. 2, p. 21–31, 2013. DOI: 10.4067/S0719-06462013000200002. Disponível em: https://cubo.ufro.cl/ojs/index.php/cubo/article/view/1306. Acesso em: 12 may. 2024.