@article{DAN_1989_306_1_a1,
     author = {M. A. Atakhodzhaev},
     title = {Nonuniqueness of the solution of an ill-posed problem for the},
     journal = {Doklady Akademii Nauk},
     pages = {15--20},
     publisher = {mathdoc},
     volume = {306},
     number = {1},
     year = {1989},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1989_306_1_a1/}
}