@article{DE_1972_8_10_a2,
     author = {V. G. Boltyanskii},
     title = {Criteria for the optimality of discrete processes},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1745--1752},
     publisher = {mathdoc},
     volume = {8},
     number = {10},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1972_8_10_a2/}
}