BibTeX

@ARTICLE{iumj59048,
    author = "Yasutaka Sibuya",
     title = "On Perturbations of Periodic Solutions",
   journal = "Indiana Univ. Math. J.",
  fjournal = "Indiana University Mathematics Journal",
    volume = 9,
      year = 1960,
     issue = 5,
     pages = "771--782",
      issn = "0022-2518",
     coden = "IUMJAB",
   mrclass = "",
}

amsrefs

\bib{iumj59048}{article}{
     author = {Sibuya, Yasutaka},
      title = {On Perturbations of Periodic Solutions},
    journal = {Indiana Univ. Math. J.},
     volume = {9},
       year = {1960},
     number = {5},
      pages = {771 \ndash 782},
}