@article{DE_1991_27_9_a0,
     author = {S. A. Aisagaliev},
     title = {Controllability of a system of differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1475--1486},
     publisher = {mathdoc},
     volume = {27},
     number = {9},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_9_a0/}
}