@article{DE_1979_15_4_a11,
     author = {V. I. Meleshko},
     title = {Perturbations of unbounded closed pseudoinverse operators},
     journal = {Differencialʹnye uravneni\^a},
     pages = {681--694},
     publisher = {mathdoc},
     volume = {15},
     number = {4},
     year = {1979},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1979_15_4_a11/}
}