@article{DAN_1964_158_5_a1,
     author = {K. V. Valikov},
     title = {Characteristic indices of solutions of differential equations in a {Banach} space},
     journal = {Doklady Akademii Nauk},
     pages = {1010--1013},
     year = {1964},
     volume = {158},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_158_5_a1/}
}