@incollection{Ammon2019,
  author    = {Ulrich Ammon},
  title     = {Empirische Untersuchungen zur Stellung der deutschen Sprache in Europa in Wirtschaft, Wissenschaft und Politik},
  series = {Deutsch als Verkehrssprache in Europa},
  publisher = {de Gruyter},
  address   = {Berlin [u.a.]},
  doi       = {10.1515/9783110622478-005},
  url       = {https://nbn-resolving.org/urn:nbn:de:bsz:mh39-86903},
  pages     = {38 -- 53},
  year      = {2019},
  language  = {de}
}