@article{DE_1968_4_11_a7,
     author = {N. F. Trubitsyn},
     title = {A test of stability of linear systems with variable coefficients},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1994--2001},
     publisher = {mathdoc},
     volume = {4},
     number = {11},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_11_a7/}
}