@article{DE_1969_5_2_a2,
     author = {P. P. Zabreiko and I. B. Ledovskaya},
     title = {On the basis of the method of {N.} {N.} {Bogoljubov} and {N.} {M.} {Krylov} for ordinary differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {240--253},
     publisher = {mathdoc},
     volume = {5},
     number = {2},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1969_5_2_a2/}
}