BibTeX

@ARTICLE{iumj25091,
    author = "David Westreich",
     title = "A Variational Theorem for Nonlinear Differential Equations",
   journal = "Indiana Univ. Math. J.",
  fjournal = "Indiana University Mathematics Journal",
    volume = 25,
      year = 1976,
     issue = 12,
     pages = "1149--1157",
      issn = "0022-2518",
     coden = "IUMJAB",
   mrclass = "",
}

amsrefs

\bib{iumj25091}{article}{
     author = {Westreich, David},
      title = {A Variational Theorem for Nonlinear Differential Equations},
    journal = {Indiana Univ. Math. J.},
     volume = {25},
       year = {1976},
     number = {12},
      pages = {1149 \ndash 1157},
}