@article{DE_1997_33_2_a11,
     author = {S. N. Popova and E. L. Tonkov},
     title = {Compatible systems and the control of {Lyapunov} exponents},
     journal = {Differencialʹnye uravneni\^a},
     pages = {226--235},
     publisher = {mathdoc},
     volume = {33},
     number = {2},
     year = {1997},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1997_33_2_a11/}
}