PERFEKT, Karl-Mikael. On M-ideals and o-O type spaces. Mathematica Scandinavica, Berkeley, CA, United States, v. 121, n. 1, p. 151–160, 2017. DOI: 10.7146/math.scand.a-96626. Disponível em: https://journals.msp.org/mscand/article/view/303. Acesso em: 24 jul. 2026.