@article{GDZPPN002336596,
title = {Hamiltonian systems, Lagrangian tori and Birkhoffs's theorem.},
journal = {Mathematische Annalen},
volume = {293},
year = {1992},
pages = {619-628},
zbl = {0735.58016},
url = {http://dml.mathdoc.fr/item/GDZPPN002336596}
}
Bialy, Misha; Polterovich, Leonid. Hamiltonian systems, Lagrangian tori and Birkhoffs's theorem.. Mathematische Annalen, Tome 293 (1992) pp. 619-628. http://gdmltest.u-ga.fr/item/GDZPPN002336596/