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@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/} }
P. G. Lasy. Characteristic vectors of linear Pfaffian systems. Differencialʹnye uravneniâ, Tome 18 (1982) no. 5, pp. 901-903. http://geodesic.mathdoc.fr/item/DE_1982_18_5_a26/