@article{DE_1982_18_5_a26,
     author = {P. G. Lasy},
     title = {Characteristic vectors of linear {Pfaffian} systems},
     journal = {Differencialʹnye uravneni\^a},
     pages = {901--903},
     publisher = {mathdoc},
     volume = {18},
     number = {5},
     year = {1982},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DE_1982_18_5_a26/}
}