@article{DAN_1973_211_3_a5,
     author = {S. G. Krein and S. Ya. L'vin},
     title = {The general initial value problem for a differential equation in {Banach} space},
     journal = {Doklady Akademii Nauk},
     pages = {530--533},
     publisher = {mathdoc},
     volume = {211},
     number = {3},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1973_211_3_a5/}
}