TY  - JOUR
AU  - Cheng, Sui Sun
AU  - Zhang, Guang
TI  - Existence of positive periodic solutions for non-autonomous functional differential equations
JO  - Electronic Journal of Differential Equations
PY  - 2001
VL  - 2001
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/EJDE_2001__2001__a81/
LA  - en
ID  - EJDE_2001__2001__a81
ER  -