@article{DE_1967_3_10_a9,
     author = {A. N. Filatov},
     title = {On averaging in systems of integro-differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1725--1731},
     publisher = {mathdoc},
     volume = {3},
     number = {10},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1967_3_10_a9/}
}