ARCHBOLD, Robert J.; KANIUTH, Eberhard. On the real rank of $C^\ast$-algebras of nilpotent locally compact groups. Mathematica Scandinavica, Berkeley, CA, United States, v. 110, n. 1, p. 99–110, 2012. DOI: 10.7146/math.scand.a-15199. Disponível em: https://journals.msp.org/mscand/article/view/498. Acesso em: 24 jul. 2026.