@article{DAN_1980_252_5_a5,
     author = {A. L. Krylov and A. E. Lifshits},
     title = {On hyperbolic systems with nonpropagating perturbations},
     journal = {Doklady Akademii Nauk},
     pages = {1048--1051},
     year = {1980},
     volume = {252},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1980_252_5_a5/}
}