@article{SM_1988_60_2_a18,
     author = {G. V. Radzievskii},
     title = {On the linear independence of the {Keldysh} derived chains for operator-valued functions analytic in a~half-plane},
     journal = {Sbornik. Mathematics},
     pages = {547--567},
     publisher = {mathdoc},
     volume = {60},
     number = {2},
     year = {1988},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_1988_60_2_a18/}
}