@article{DE_1977_13_11_a6,
     author = {A. B. Kurzhanskii},
     title = {Informational sets of control systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1957--1965},
     publisher = {mathdoc},
     volume = {13},
     number = {11},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_11_a6/}
}