@article{DAN_1968_179_1_a3,
     author = {V. M. Millionshchikov},
     title = {A metric theory of linear systems of differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {20--23},
     publisher = {mathdoc},
     volume = {179},
     number = {1},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1968_179_1_a3/}
}