@article{DE_1972_8_8_a23,
     author = {T. B. Kopeikina},
     title = {The identifiability of linear nonstationary systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1507--1510},
     publisher = {mathdoc},
     volume = {8},
     number = {8},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_8_a23/}
}