@article{DAN_1970_195_3_a13,
     author = {\`E. M. Saak},
     title = {On the stability of the {Dirichlet} and {Neumann} problems},
     journal = {Doklady Akademii Nauk},
     pages = {564--566},
     publisher = {mathdoc},
     volume = {195},
     number = {3},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1970_195_3_a13/}
}