TY  - JOUR
AU  - Chengfu Che
AU  - Xiaoping Xue
TI  - Periodic solutions for second order Hamiltonian systems
 on an arbitrary energy surface
JO  - Annales Polonici Mathematici
PY  - 2012
SP  - 1
EP  - 12
VL  - 105
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/ap105-1-1/
DO  - 10.4064/ap105-1-1
LA  - en
ID  - 10_4064_ap105_1_1
ER  -