@article{DAN_1991_319_5_a4,
     author = {M. K. Bugir},
     title = {A connection between the nonvariability of solutions and ill-posed},
     journal = {Doklady Akademii Nauk},
     pages = {1053--1056},
     publisher = {mathdoc},
     volume = {319},
     number = {5},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_319_5_a4/}
}