DELANOË, P. Perturbing fully nonlinear second order elliptic equations. Topological Methods in Nonlinear Analysis, [S. l.], v. 20, n. 1, p. 63–75, 2002. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2002.025. Acesso em: 25 apr. 2024.