FISCELLA, A. Saddle point solutions for non-local elliptic operators. Topological Methods in Nonlinear Analysis, [S. l.], v. 44, n. 2, p. 527–538, 2016. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2014.059. Acesso em: 23 apr. 2024.