@article{IVM_1972_1_a6,
     author = {S. F. Morozov},
     title = {Necessary conditions for the extremum of two-dimensional variational problems on a~collection of discontinuous functions},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {55--63},
     publisher = {mathdoc},
     number = {1},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1972_1_a6/}
}