@article{DE_2005_41_12_a1,
     author = {N. A. Izobov},
     title = {On the {Smallness} of {Perturbations} {Preserving} the {Higher} {Exponent} of a {Linear} {Differential} {System}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1592--1596},
     publisher = {mathdoc},
     volume = {41},
     number = {12},
     year = {2005},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_2005_41_12_a1/}
}