@article{RM_1962_17_3_a14,
     author = {A. Yu. Levin},
     title = {On a stability criterion},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     year = {1962},
     volume = {17},
     number = {3},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/RM_1962_17_3_a14/}
}