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@article{IVM_1977_2_a5, author = {L. E. Zabello}, title = {On the question of the controllability of nonstationary {systems.~II}}, journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika}, pages = {27--36}, publisher = {mathdoc}, number = {2}, year = {1977}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/IVM_1977_2_a5/} }
L. E. Zabello. On the question of the controllability of nonstationary systems.~II. Izvestiâ vysših učebnyh zavedenij. Matematika, no. 2 (1977), pp. 27-36. http://geodesic.mathdoc.fr/item/IVM_1977_2_a5/