@book{steiner-ga17-de,
  author = {Steiner, Rudolf},
  title = {Die Schwelle der geistigen Welt (1913)},
  series = {Rudolf Steiner Gesamtausgabe},
  number = {17},
  edition = {9},
  publisher = {Rudolf Steiner Verlag},
  address = {Basel},
  year = {2020},
  pagetotal = {134},
  isbn = {978-3-7274-0171-8},
  language = {german},
}

@book{steiner-ga17-en-gpp1922,
  author = {Steiner, Rudolf},
  title = {The Threshold of the Spiritual World},
  publisher = {G. P. Putnam's Sons},
  year = {1922},
  language = {english},
  note = {GA 17; edition code GPP1922},
}

@online{anthroposophyai-ga17,
  author = {Steiner, Rudolf},
  title = {Die Schwelle der geistigen Welt (1913) (GA 17), as served by anthroposophy.ai},
  url = {https://anthroposophy.ai/contents/17/},
  urldate = {2026-10-21},
  organization = {anthroposophy.ai},
  note = {Rudolf Steiner, Die Schwelle der geistigen Welt (1913) (GA 17), as served by anthroposophy.ai, https://anthroposophy.ai/ga/17/, register entry https://anthroposophy.ai/contents/17/, status as of 2026-10-21: German served; English editions GPP1922.},
}