@article{DAN_1957_114_5_a8,
     author = {P. I. Koval'},
     title = {On the asymptotic behaviour of solutions of linear difference equations and linear differential equations},
     journal = {Doklady Akademii Nauk},
     pages = {949--952},
     publisher = {mathdoc},
     volume = {114},
     number = {5},
     year = {1957},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1957_114_5_a8/}
}