@article{INTO_2017_138_a8,
     author = {M. E. Shirokov and A. V. Bulinski},
     title = {Lower estimates for distances from a given quantum channel to  certain classes of quantum channels},
     journal = {Itogi nauki i tehniki. Sovremenna\^a matematika i e\"e prilo\v{z}eni\^a. Temati\v{c}eskie obzory},
     pages = {125--131},
     publisher = {mathdoc},
     volume = {138},
     year = {2017},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/INTO_2017_138_a8/}
}