SZWEDEK, R. Interpolation of approximation numbers between Hilbert spaces. Annales Fennici Mathematici, [S. l.], v. 40, n. 1, p. 343–360, 2015. DOI: 10.5186/aasfm.2015.4014. Disponível em: https://afm.journal.fi/article/view/135545. Acesso em: 22 nov. 2024.