@article{DE_1980_16_9_a18,
     author = {I. N. Sergeev},
     title = {Invariance of central exponents with respect to perturbations which approach zero at infinity},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1719},
     publisher = {mathdoc},
     volume = {16},
     number = {9},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1980_16_9_a18/}
}