@article{KYB_1973_9_1_a2,
     author = {Soukup, V\'aclav},
     title = {Linear nonstationary system with discrete-time input},
     journal = {Kybernetika},
     pages = {30--41},
     year = {1973},
     volume = {9},
     number = {1},
     mrnumber = {0332257},
     zbl = {0253.93019},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/KYB_1973_9_1_a2/}
}