@article{DE_1997_33_7_a20,
     author = {B. F. Ivanov},
     title = {A frequency criterion for smoothness, with respect to the parameters, of solutions of a class of linear systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1001},
     publisher = {mathdoc},
     volume = {33},
     number = {7},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1997_33_7_a20/}
}