TY  - JOUR
AU  - Maria Letizia Bertotti
TI  - Multiplicity of Subharmonic solutions of Forces Hamiltonian systems near an equilibrium.
JO  - Manuscripta mathematica
PY  - 1989
SP  - 389
EP  - 402
VL  - 64
IS  - 2
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/MM2_1989__64_2_155414/
ID  - MM2_1989__64_2_155414
ER  -