@article{DE_1970_6_6_a3,
     author = {I. A. Pavlyuk},
     title = {Asymptotic integration of certain classes of nonautonomous systems of differential equations by means of differential invariants},
     journal = {Differencialʹnye uravneni\^a},
     pages = {975--988},
     publisher = {mathdoc},
     volume = {6},
     number = {6},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1970_6_6_a3/}
}