@article{oai:repository.dl.itc.u-tokyo.ac.jp:00039934,
 author = {Hukuhara, Masuo},
 issue = {4},
 journal = {Journal of the Faculty of Science, University of Tokyo. Sect. 1, Mathematics, astronomy, physics, chemistry = 東京大學理學部紀要. 第1類, 數學, 天文學, 物理學, 化學},
 month = {Feb},
 pages = {437--447},
 title = {Sur les equations differentielles periodiques non lineaires},
 volume = {7},
 year = {1957}
}