MOROZ, V. Solutions of superlinear at zero elliptic equations via Morse theory. Topological Methods in Nonlinear Analysis, [S. l.], v. 10, n. 2, p. 387–397, 1997. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1997.039. Acesso em: 28 mar. 2024.