@article{RM_2004_59_2_a14,
     author = {A. S. Holevo and M. E. Shirokov},
     title = {The additivity problem for constrained quantum channels},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {385--387},
     publisher = {mathdoc},
     volume = {59},
     number = {2},
     year = {2004},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_2004_59_2_a14/}
}