NAJATI, A.; FAROUGHI, M. H.; RAHIMI, A. $g$-frames and stability of $g$-frames in Hilbert spaces. Methods of Functional Analysis and Topology, [S. l.], v. 14, n. 3, p. 271–286, 2008. Disponível em: https://zen.imath.kiev.ua/index.php/mfat/article/view/390. Acesso em: 18 dec. 2025.