@article{DE_1993_29_2_a3,
     author = {A. V. Metel'skii},
     title = {Parametric criteria for functional observability and functional attainability of differential-difference systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {219--225},
     publisher = {mathdoc},
     volume = {29},
     number = {2},
     year = {1993},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1993_29_2_a3/}
}