@article{DE_1968_4_3_a5,
     author = {A. K. Lopatin},
     title = {The algebraic reducibility of systems of linear differential equations. {I}},
     journal = {Differencialʹnye uravneni\^a},
     pages = {439--445},
     publisher = {mathdoc},
     volume = {4},
     number = {3},
     year = {1968},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1968_4_3_a5/}
}