@article{DE_1984_20_3_a4,
     author = {M. Kh. Lantsman},
     title = {Formal representations of solutions of a class of linear homogeneous differential equations},
     journal = {Differencialʹnye uravneni\^a},
     pages = {398--408},
     publisher = {mathdoc},
     volume = {20},
     number = {3},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1984_20_3_a4/}
}