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@article{IVM_1976_12_a3, author = {L. E. Zabello}, title = {On the question of the controllability of nonstationary {systems.~I}}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {30--37}, publisher = {mathdoc}, number = {12}, year = {1976}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1976_12_a3/} }
L. E. Zabello. On the question of the controllability of nonstationary systems.~I. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 12 (1976), pp. 30-37. http://geodesic.mathdoc.fr/item/IVM_1976_12_a3/