@article{DAN_1970_192_5_a14,
     author = {Nguy\^en van Dao},
     title = {On the oscillations of systems which are nearly essentially nonlinear},
     journal = {Doklady Akademii Nauk},
     pages = {1004--1006},
     publisher = {mathdoc},
     volume = {192},
     number = {5},
     year = {1970},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1970_192_5_a14/}
}