@article{DAN_1982_264_4_a11,
     author = {A. V. Kostin and I. E. Vitrichenko},
     title = {Generalization of {Ljapunov's} stability theorem in the case of one zero characteristic exponent for nonautonomous systems},
     journal = {Doklady Akademii Nauk},
     pages = {819--822},
     publisher = {mathdoc},
     volume = {264},
     number = {4},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1982_264_4_a11/}
}