TY  - JOUR
AU  - Wang, Genqiang
AU  - Cheng, Sui Sun
TI  - Even periodic solutions of higher order duffing differential equations
JO  - Czechoslovak Mathematical Journal
PY  - 2007
SP  - 331
EP  - 343
VL  - 57
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/CMJ_2007__57_1_a24/
LA  - en
ID  - CMJ_2007__57_1_a24
ER  -