@article{ZVMMF_1978_18_4_a10,
     author = {E. N. Or\"el},
     title = {Approximation of the {Bellman} function by step functions},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {916--927},
     publisher = {mathdoc},
     volume = {18},
     number = {4},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1978_18_4_a10/}
}