@article{DE_1986_22_9_a5,
     author = {Yu. A. Mitropol'skii and V. L. Kulik},
     title = {Differentiable invariant manifolds of dynamical systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1523--1532},
     publisher = {mathdoc},
     volume = {22},
     number = {9},
     year = {1986},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1986_22_9_a5/}
}