@article{DE_1976_12_11_a14,
     author = {V. A. Tyshkevich},
     title = {Asymptotic equivalence of linear differential systems with retarded argument},
     journal = {Differencialʹnye uravneni\^a},
     pages = {2039--2043},
     publisher = {mathdoc},
     volume = {12},
     number = {11},
     year = {1976},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1976_12_11_a14/}
}