@article{DE_1969_5_5_a6,
     author = {N. G. Bulgakov},
     title = {On the question of stability under constantly acting perturbations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {856--861},
     publisher = {mathdoc},
     volume = {5},
     number = {5},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1969_5_5_a6/}
}