TY  - JOUR
AU  - M. Sabatini
TI  - Period function's convexity for Hamiltonian centers
 with separable variables
JO  - Annales Polonici Mathematici
PY  - 2005
SP  - 153
EP  - 163
VL  - 85
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/articles/10.4064/ap85-2-5/
DO  - 10.4064/ap85-2-5
LA  - en
ID  - 10_4064_ap85_2_5
ER  -