GREEN, William L.; MORLEY, T. D. Operator means, fixed points, and the norm convergence of monotone approximants. MATHEMATICA SCANDINAVICA, [S. l.], v. 60, p. 202–218, 1987. DOI: 10.7146/math.scand.a-12180. Disponível em: https://tidsskrift.dk/math/article/view/12180. Acesso em: 14 aug. 2026.