@article{DE_1973_9_2_a1,
     author = {\`E. I. Grudo},
     title = {A certain autonomous system of differential equations with zero roots of the characteristic equation},
     journal = {Differencialʹnye uravneni\^a},
     pages = {211--219},
     publisher = {mathdoc},
     volume = {9},
     number = {2},
     year = {1973},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1973_9_2_a1/}
}