BibTeX

@ARTICLE{iumj58056,
    author = "A. Zygmund",
     title = "On the Preservation of Classes of Functions",
   journal = "Indiana Univ. Math. J.",
  fjournal = "Indiana University Mathematics Journal",
    volume = 8,
      year = 1959,
     issue = 6,
     pages = "889--895",
      issn = "0022-2518",
     coden = "IUMJAB",
   mrclass = "",
}

amsrefs

\bib{iumj58056}{article}{
     author = {Zygmund, A.},
      title = {On the Preservation of Classes of Functions},
    journal = {Indiana Univ. Math. J.},
     volume = {8},
       year = {1959},
     number = {6},
      pages = {889 \ndash 895},
}