@article{DVMG_2000_1_1_a5,
     author = {G. G. Durnov},
     title = {The estimation for the indexes of linear differential systems with perturbation},
     journal = {Dalʹnevosto\v{c}nyj matemati\v{c}eskij \v{z}urnal},
     pages = {43--50},
     publisher = {mathdoc},
     volume = {1},
     number = {1},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DVMG_2000_1_1_a5/}
}