GROH, Ulrich; KÜMMERER, Burkhard. Bibounded operators on W*-algebras. MATHEMATICA SCANDINAVICA, [S. l.], v. 50, p. 269–285, 1982. DOI: 10.7146/math.scand.a-11959. Disponível em: https://www.mscand.dk/article/view/11959. Acesso em: 5 dec. 2025.