@article{ZVMMF_1990_30_4_a0,
     author = {D. L. Kondratiev and A. V. Lotov},
     title = {External estimates and construction of attainability sets for controlled systems},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {483--490},
     publisher = {mathdoc},
     volume = {30},
     number = {4},
     year = {1990},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1990_30_4_a0/}
}