@article{DAN_1965_163_5_a8,
     author = {R. K. Romanovskii},
     title = {Stability of solutions to the {Cauchy} problem for linear differential equations of the hyperbolic type},
     journal = {Doklady Akademii Nauk},
     pages = {1077--1080},
     publisher = {mathdoc},
     volume = {163},
     number = {5},
     year = {1965},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1965_163_5_a8/}
}