@article{ZVMMF_1992_32_12_a8,
     author = {N. N. Pisaruk},
     title = {The boundaries of submodular functions},
     journal = {\v{Z}urnal vy\v{c}islitelʹnoj matematiki i matemati\v{c}eskoj fiziki},
     pages = {1940--1955},
     year = {1992},
     volume = {32},
     number = {12},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZVMMF_1992_32_12_a8/}
}