@article{DAN_1971_197_6_a1,
     author = {M. A. Gol'dman and S. N. Krachkovskii},
     title = {On a class of perturbations of a linear closed operator with a closed range},
     journal = {Doklady Akademii Nauk},
     pages = {1243--1246},
     publisher = {mathdoc},
     volume = {197},
     number = {6},
     year = {1971},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1971_197_6_a1/}
}