TY  - JOUR
AU  - E. N. Krupchik
TI  - Lower characteristic exponents of nontrivial solutions of Pfaffian systems
JO  - Differencialʹnye uravneniâ
PY  - 1999
SP  - 899
EP  - 908
VL  - 35
IS  - 7
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1999_35_7_a4/
LA  - ru
ID  - DE_1999_35_7_a4
ER  -