@article{DE_1968_4_4_a13,
     author = {A. M. Stakhy},
     title = {The returnability of points and regions in partially ordered dynamical systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {693--701},
     publisher = {mathdoc},
     volume = {4},
     number = {4},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_4_a13/}
}