@article{DE_1984_20_6_a3,
     author = {V. P. Igumnov},
     title = {Representation of solutions of differential equations by modified {Lie} series},
     journal = {Differencialʹnye uravneni\^a},
     pages = {952--958},
     publisher = {mathdoc},
     volume = {20},
     number = {6},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_6_a3/}
}