@article{DAN_1971_196_5_a8,
     author = {V. R. Portnov},
     title = {Normal solvability of an abstract nonlinear problem. {Applications} to the solution of boundary value problems for partial differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {1028--1031},
     publisher = {mathdoc},
     volume = {196},
     number = {5},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_196_5_a8/}
}