@article{FAA_1991_25_1_a8,
     author = {S. R. Gordeev},
     title = {On the index and the homotopic classification of {Noetherian} operators with a finite group of shifts},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {66--68},
     publisher = {mathdoc},
     volume = {25},
     number = {1},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1991_25_1_a8/}
}