@article{DE_1978_14_12_a11,
     author = {N. N. Stepanyuk},
     title = {Some problems of controllability and observability of two-parameter discrete systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2190--2195},
     publisher = {mathdoc},
     volume = {14},
     number = {12},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1978_14_12_a11/}
}