DING, Y. Infinitely many entire solutions of an elliptic system with symmetry. Topological Methods in Nonlinear Analysis, [S. l.], v. 9, n. 2, p. 313–323, 1997. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1997.016. Acesso em: 25 apr. 2024.