@article{DE_1981_17_2_a19,
     author = {V. Kh. Froim},
     title = {Linear systems of first-order partial differential equations with semiregular degeneration on a hyperplane},
     journal = {Differencialʹnye uravneni\^a},
     pages = {373--382},
     publisher = {mathdoc},
     volume = {17},
     number = {2},
     year = {1981},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1981_17_2_a19/}
}