@article{GDZPPN002222930,
title = {Periodic Solutions of Asymptotically Linear Hamiltonian Systems.},
journal = {Manuscripta mathematica},
volume = {31},
year = {1980},
pages = {149-190},
zbl = {0443.70019},
url = {http://dml.mathdoc.fr/item/GDZPPN002222930}
}
Amann, Herbert; Zehnder, Eduard. Periodic Solutions of Asymptotically Linear Hamiltonian Systems.. Manuscripta mathematica, Tome 31 (1980) pp. 149-190. http://gdmltest.u-ga.fr/item/GDZPPN002222930/