RUNDE, Volker. Dual Banach algebras: Connes-amenability, normal, virtual diagonals, and injectivity of the predual bimodule. Mathematica Scandinavica, Berkeley, CA, United States, v. 95, n. 1, p. 124–144, 2004. DOI: 10.7146/math.scand.a-14452. Disponível em: https://journals.msp.org/mscand/article/view/767. Acesso em: 24 jul. 2026.