@article{05725777,
title = {Existence of periodic solutions of linear Hamiltonian systems with sublinear perturbation.},
journal = {Boundary Value Problems [electronic only]},
volume = {2010},
year = {2010},
doi = {10.1155/2010/945421},
zbl = {1201.37093},
language = {en},
url = {http://dml.mathdoc.fr/item/05725777}
}
Han, Zhiqing. Existence of periodic solutions of linear Hamiltonian systems with sublinear perturbation.. Boundary Value Problems [electronic only], Tome 2010 (2010) . doi : 10.1155/2010/945421. http://gdmltest.u-ga.fr/item/05725777/