LIMA, Vegard. Approximation properties for dual spaces. Mathematica Scandinavica, Berkeley, CA, United States, v. 93, n. 2, p. 297–312, 2003. DOI: 10.7146/math.scand.a-14425. Disponível em: https://journals.msp.org/mscand/article/view/794. Acesso em: 25 jul. 2026.