LI, C.; AGARWAL, R. P.; OU, Z.-Q. Existence of three nontrivial solutions for a class of fourth-order elliptic equations. Topological Methods in Nonlinear Analysis, [S. l.], v. 51, n. 2, p. 331–344, 2018. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2018.001. Acesso em: 28 mar. 2024.