@article{DAN_1965_160_6_a9,
     author = {Yu. I. Neimark and L. P. Shilnikov},
     title = {A condition for the generation of periodic motions},
     journal = {Doklady Akademii Nauk},
     pages = {1261--1264},
     publisher = {mathdoc},
     volume = {160},
     number = {6},
     year = {1965},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1965_160_6_a9/}
}