BibTeX

@ARTICLE{iumj28061,
    author = "E. Podolak and David Westreich",
     title = "Systems of First Order Differential Equations with Global Periodic Solutions",
   journal = "Indiana Univ. Math. J.",
  fjournal = "Indiana University Mathematics Journal",
    volume = 28,
      year = 1979,
     issue = 6,
     pages = "869--882",
      issn = "0022-2518",
     coden = "IUMJAB",
   mrclass = "",
}

amsrefs

\bib{iumj28061}{article}{
     author = {Podolak, E.},
     author = {Westreich, David},
      title = {Systems of First Order Differential Equations with Global Periodic Solutions},
    journal = {Indiana Univ. Math. J.},
     volume = {28},
       year = {1979},
     number = {6},
      pages = {869 \ndash 882},
}