@article{DE_1991_27_5_a24,
     author = {E. K. Makarov},
     title = {On a criterion for joint behavior of higher sigma exponents of a triangular system and the system of its diagonal approximation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {910--911},
     year = {1991},
     volume = {27},
     number = {5},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1991_27_5_a24/}
}