WANG, Zhi-Qiang; WILLEM, Michael. A multiplicity result for the generalized Kadomtsev-Petviashvili equation. Topological Methods in Nonlinear Analysis, [S. l.], v. 7, n. 2, p. 261–270, 1996. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1996.012. Acesso em: 8 jul. 2025.