BibTeX

@ARTICLE{iumj15018,
    author = "R. Phillips and Leonard Sarason",
     title = "Singular Symmetric Positive First Order Differential Operators",
   journal = "Indiana Univ. Math. J.",
  fjournal = "Indiana University Mathematics Journal",
    volume = 15,
      year = 1966,
     issue = 2,
     pages = "235--271",
      issn = "0022-2518",
     coden = "IUMJAB",
   mrclass = "",
}

amsrefs

\bib{iumj15018}{article}{
     author = {Phillips, R.},
     author = {Sarason, Leonard},
      title = {Singular Symmetric Positive First Order Differential Operators},
    journal = {Indiana Univ. Math. J.},
     volume = {15},
       year = {1966},
     number = {2},
      pages = {235 \ndash 271},
}