SCHIPPERS, E. The derivative of the Nehari functional. Annales Fennici Mathematici, [S. l.], v. 35, n. 1, p. 291–307, 2010. DOI: 10.5186/aasfm.2010.3518. Disponível em: https://afm.journal.fi/article/view/135308. Acesso em: 27 apr. 2025.