@article{DE_1974_10_3_a15,
     author = {R. R. Akhmerov and M. I. Kamenskii},
     title = {On the second theorem of {N.\,N.~Bogoljubov} in the averaging principle for functional-differential equations of neutral type},
     journal = {Differencialʹnye uravneni\^a},
     pages = {537--540},
     publisher = {mathdoc},
     volume = {10},
     number = {3},
     year = {1974},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1974_10_3_a15/}
}