@article{DAN_1978_243_2_a0,
     author = {U. Raitums},
     title = {The extension of extremal problems connected with a linear elliptic equation},
     journal = {Doklady Akademii Nauk},
     pages = {281--283},
     publisher = {mathdoc},
     volume = {243},
     number = {2},
     year = {1978},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1978_243_2_a0/}
}