@article{DE_1977_13_6_a4,
     author = {A. I. Kobrin and Yu. G. Martynenko},
     title = {Asymptotic solution of a weakly nonlinear system},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1008--1019},
     publisher = {mathdoc},
     volume = {13},
     number = {6},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_6_a4/}
}