@article{DAN_1958_120_3_a2,
     author = {I. V. Gel'man},
     title = {On some non-linear operator},
     journal = {Doklady Akademii Nauk},
     pages = {454--456},
     publisher = {mathdoc},
     volume = {120},
     number = {3},
     year = {1958},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1958_120_3_a2/}
}