SHIOJI, N.; WATANABE, K. Radial symmetry of $n$-mode positive solutions for semilinear elliptic equations in a disc and its application to the Hénon equation. Topological Methods in Nonlinear Analysis, [S. l.], v. 43, n. 1, p. 269–285, 2016. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2014.016. Acesso em: 22 jan. 2022.