@article{DE_1978_14_11_a16,
     author = {A. P. Ivanov},
     title = {On the problem of observation of perturbed systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2071--2072},
     publisher = {mathdoc},
     volume = {14},
     number = {11},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_11_a16/}
}