@article{BSMF_1981__109__297_0,
     author = {Ekeland, Ivar},
     title = {Oscillations de syst\`emes hamiltoniens non lin\'eaires. {III}},
     journal = {Bulletin de la Soci\'et\'e Math\'ematique de France},
     pages = {297--330},
     publisher = {Soci\'et\'e math\'ematique de France},
     volume = {109},
     year = {1981},
     doi = {10.24033/bsmf.1944},
     mrnumber = {84m:58112},
     zbl = {0514.70025},
     language = {fr},
     url = {http://archive.numdam.org/articles/10.24033/bsmf.1944/}
}