@article{DAN_1980_255_3_a2,
     author = {D. M. Fage},
     title = {Approximate solution of a nonlinear problem with constraint for a two- dimensional elliptic equation},
     journal = {Doklady Akademii Nauk},
     pages = {531--534},
     publisher = {mathdoc},
     volume = {255},
     number = {3},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_255_3_a2/}
}