@article{DAN_1974_215_4_a6,
     author = {E. S. Levitin},
     title = {On differential properties of the optimum value or parametric problems of mathematical programming},
     journal = {Doklady Akademii Nauk},
     pages = {792--795},
     publisher = {mathdoc},
     volume = {215},
     number = {4},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1974_215_4_a6/}
}