TY  - JOUR
AU  - N. A. Izobov
TI  - On the existence of linear Pfaffian systems whose set of lower characteristic vectors has a positive plane measure
JO  - Differencialʹnye uravneniâ
PY  - 1997
SP  - 1623
EP  - 1630
VL  - 33
IS  - 12
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1997_33_12_a5/
LA  - ru
ID  - DE_1997_33_12_a5
ER  -