https://digital.katalog.queersearch.org/s/katalog/item/41133, https://digital.katalog.queersearch.org/s/katalog/item/41134, and https://digital.katalog.queersearch.org/s/katalog/item/42197, “Homosexuellen-Verfolgung in Hamburg 1919-1969”, https://digital.katalog.queersearch.org/s/katalog/item/46482, QueerSearch, accessed 29. April 2025, https://digital.katalog.queersearch.org/s/katalog/item/20118