https://digital.katalog.queersearch.org/s/katalog/item/39056 and https://digital.katalog.queersearch.org/s/katalog/item/43883, “Perversions Sexuelles”, https://digital.katalog.queersearch.org/s/katalog/item/50672, QueerSearch, accessed 29. April 2025, https://digital.katalog.queersearch.org/s/katalog/item/29658