@article{DE_1974_10_3_a8,
     author = {B. A. Shcherbakov and L. V. Koreneva},
     title = {The preservation of the nature of the recurrence of the solutions of differential equations under perturbations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {470--475},
     publisher = {mathdoc},
     volume = {10},
     number = {3},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1974_10_3_a8/}
}