@article{DE_1973_9_5_a20,
     author = {G. A. Kalyabin},
     title = {A necessary and sufficient condition for the discreteness of the spectrum of a monomial operation in the matrix case},
     journal = {Differencialʹnye uravneni\^a},
     pages = {951--954},
     year = {1973},
     volume = {9},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_5_a20/}
}