@article{DE_1977_13_4_a17,
     author = {I. M. Burkin},
     title = {A test for the absolute stability of oscillations in control systems with a nonstationary linear part},
     journal = {Differencialʹnye uravneni\^a},
     pages = {735--737},
     publisher = {mathdoc},
     volume = {13},
     number = {4},
     year = {1977},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1977_13_4_a17/}
}