@article{DAN_1964_157_6_a7,
     author = {O. A. Oleinik},
     title = {On a problem of {G.~Fichera}},
     journal = {Doklady Akademii Nauk},
     pages = {1297--1300},
     publisher = {mathdoc},
     volume = {157},
     number = {6},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_157_6_a7/}
}