@article{ZVMMF_1964_4_1_a9,
     author = {I. A. Bakhtin},
     title = {On an extremal problem},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {120--135},
     publisher = {mathdoc},
     volume = {4},
     number = {1},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1964_4_1_a9/}
}