BENCI, V.; FORTUNATO, D. Matter and electromagnetic fields: remarks on the dualistic and unitarian standpoints. Topological Methods in Nonlinear Analysis, [S. l.], v. 25, n. 1, p. 23–40, 2005. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2005.002. Acesso em: 22 lip. 2024.