@article{RM_1964_19_6_a26,
     author = {P. E. Sobolevskii},
     title = {Second order equations in {Banach} space with a~small parameter at the higher derivative},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     publisher = {mathdoc},
     volume = {19},
     number = {6},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1964_19_6_a26/}
}