TY  - JOUR
AU  - È. I. Grudo
TI  - Bifurcation equations for the existence of periodic solutions of periodic Pfaffian systems
JO  - Differencialʹnye uravneniâ
PY  - 1985
SP  - 1857
EP  - 1867
VL  - 21
IS  - 11
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1985_21_11_a2/
LA  - ru
ID  - DE_1985_21_11_a2
ER  -