New Characterizations of Operator-Valued Bases on Hilbert Spaces. Analysis in Theory and Applications, [S. l.], v. 33, n. 2, p. 157–177, 2017. DOI: 10.4208/ata.2017.v33.n2.6. Disponível em: https://global-sci.com/index.php/ata/article/view/8117. Acesso em: 5 dec. 2025.