@article{DE_1974_10_5_a19,
     author = {T. B. Kopeikina and V. V. Mulyarchick},
     title = {The observability and identifiability of systems with lag},
     journal = {Differencialʹnye uravneni\^a},
     pages = {933--935},
     publisher = {mathdoc},
     volume = {10},
     number = {5},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1974_10_5_a19/}
}