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@article{DE_1993_29_5_a23, author = {V. G. Romanovsky}, title = {On the calculation of {Lyapunov} quantities in the case of two purely imaginary roots}, journal = {Differencialʹnye uravneni\^a}, pages = {910--912}, publisher = {mathdoc}, volume = {29}, number = {5}, year = {1993}, language = {ru}, url = {http://geodesic.mathdoc.fr/item/DE_1993_29_5_a23/} }
V. G. Romanovsky. On the calculation of Lyapunov quantities in the case of two purely imaginary roots. Differencialʹnye uravneniâ, Tome 29 (1993) no. 5, pp. 910-912. http://geodesic.mathdoc.fr/item/DE_1993_29_5_a23/