@article{DE_1973_9_6_a8,
     author = {S. Yu. Pilyugin},
     title = {The limit sets of two-dimensional unstable manifolds in three-dimensional systems of differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1068--1072},
     publisher = {mathdoc},
     volume = {9},
     number = {6},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_6_a8/}
}