KAIJSER, Sten. A note on dual Banach spaces. Mathematica Scandinavica, Berkeley, CA, United States, v. 41, p. 325–330, 1977. DOI: 10.7146/math.scand.a-11725. Disponível em: https://journals.msp.org/mscand/article/view/1922. Acesso em: 25 jul. 2026.