@article{702354,
title = {Hamiltonian systems with periodic nonlinearities},
booktitle = {Equadiff 7},
series = {GDML\_Books},
publisher = {BSB B.G. Teubner Verlagsgesellschaft},
address = {Leipzig},
year = {1990},
pages = {131-134},
zbl = {0721.58010},
url = {http://dml.mathdoc.fr/item/702354}
}
Szulkin, A. Hamiltonian systems with periodic nonlinearities, dans Equadiff 7, GDML_Books, (1990), pp. 131-134. http://gdmltest.u-ga.fr/item/702354/