BibTeX

@ARTICLE{iumj55014,
    author = "Robert Gambill and Jack Hale",
     title = "Subharmonic and Ultraharmonic Solutions for Weakly Non-Linear Systems",
   journal = "Indiana Univ. Math. J.",
  fjournal = "Indiana University Mathematics Journal",
    volume = 5,
      year = 1956,
     issue = 2,
     pages = "353--394",
      issn = "0022-2518",
     coden = "IUMJAB",
   mrclass = "",
}

amsrefs

\bib{iumj55014}{article}{
     author = {Gambill, Robert},
     author = {Hale, Jack},
      title = {Subharmonic and Ultraharmonic Solutions for Weakly Non-Linear Systems},
    journal = {Indiana Univ. Math. J.},
     volume = {5},
       year = {1956},
     number = {2},
      pages = {353 \ndash 394},
}