@article{GDZPPN002223252,
title = {T-Periodic Solutions of Time Dependent Hamiltonian Systems with a Potential Vanishing at Infinity.},
journal = {Manuscripta mathematica},
volume = {31},
year = {1980},
pages = {327-338},
zbl = {0467.35009},
url = {http://dml.mathdoc.fr/item/GDZPPN002223252}
}
Thews, Klaus. T-Periodic Solutions of Time Dependent Hamiltonian Systems with a Potential Vanishing at Infinity.. Manuscripta mathematica, Tome 31 (1980) pp. 327-338. http://gdmltest.u-ga.fr/item/GDZPPN002223252/