POPESCU, Gelu. Von Neumann inequality for $(B(\mathscr{H})^n)_1$. Mathematica Scandinavica, Berkeley, CA, United States, v. 68, p. 292–304, 1991. DOI: 10.7146/math.scand.a-12363. Disponível em: https://journals.msp.org/mscand/article/view/1267. Acesso em: 24 jul. 2026.