KATIĆ, J.; MILINKOVIĆ, D.; NIKOLIĆ, J. Spectral numbers and manifolds with boundary. Topological Methods in Nonlinear Analysis, [S. l.], v. 55, n. 2, p. 617–653, 2020. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2019.108. Acesso em: 19 apr. 2024.