@article{MS2_1987__60_167017,
     author = {William L. Green and T.D. Morley},
     title = {Operator means, fixed points, and the norm convergence of monotone approximants.},
     journal = {Mathematica Scandinavica},
     pages = {202--218},
     publisher = {mathdoc},
     volume = {60},
     year = {1987},
     zbl = {0663.47017},
     url = {http://geodesic.mathdoc.fr/item/MS2_1987__60_167017/}
}