@article{DAN_1971_196_3_a4,
     author = {R. I. Kachurovskii},
     title = {On nonlinear operators whose ranges are subspaces},
     journal = {Doklady Akademii Nauk},
     pages = {508--511},
     publisher = {mathdoc},
     volume = {196},
     number = {3},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_196_3_a4/}
}