@article{DE_1970_6_3_a17,
     author = {Yu. S. Bogdanov and A. F. Naumovich},
     title = {The relative distribution of the solutions of two stationary linear differential systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {552--554},
     publisher = {mathdoc},
     volume = {6},
     number = {3},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_3_a17/}
}