@article{DE_1998_34_10_a4,
     author = {E. K. Makarov},
     title = {On the discreteness of asymptotic invariants of linear differential systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1322--1331},
     publisher = {mathdoc},
     volume = {34},
     number = {10},
     year = {1998},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1998_34_10_a4/}
}