@article{DE_1989_25_4_a5,
     author = {O. G. Illarionova},
     title = {The central exponent of a linear system of differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {599--604},
     publisher = {mathdoc},
     volume = {25},
     number = {4},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1989_25_4_a5/}
}