@article{DAN_1971_198_1_a2,
     author = {V. M. Brodskii},
     title = {On operator nodes and their characteristic functions},
     journal = {Doklady Akademii Nauk},
     pages = {16--19},
     publisher = {mathdoc},
     volume = {198},
     number = {1},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_198_1_a2/}
}