@article{DE_1999_35_10_a11,
     author = {I. N. Sergeev},
     title = {A lower bound for the minimal exponent of a three-dimensional system},
     journal = {Differencialʹnye uravneni\^a},
     pages = {1387--1397},
     publisher = {mathdoc},
     volume = {35},
     number = {10},
     year = {1999},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1999_35_10_a11/}
}