BibTeX

@ARTICLE{iumj19004,
    author = "L. Sibner",
     title = "A Generalization of the Morse Index Theorem to a Class of Degenerate Elliptic Operators",
   journal = "Indiana Univ. Math. J.",
  fjournal = "Indiana University Mathematics Journal",
    volume = 19,
      year = 1970,
     issue = 1,
     pages = "37--40",
      issn = "0022-2518",
     coden = "IUMJAB",
   mrclass = "",
}

amsrefs

\bib{iumj19004}{article}{
     author = {Sibner, L.},
      title = {A Generalization of the Morse Index Theorem to a Class of Degenerate Elliptic Operators},
    journal = {Indiana Univ. Math. J.},
     volume = {19},
       year = {1970},
     number = {1},
      pages = {37 \ndash 40},
}