https://digital.katalog.queersearch.org/s/katalog/item/37278, https://digital.katalog.queersearch.org/s/katalog/item/37285, and https://digital.katalog.queersearch.org/s/katalog/item/37286, “Die Freundin 1927 - Ausgabe 17”, QueerSearch, accessed 16. Juni 2025, https://digital.katalog.queersearch.org/s/katalog/item/3459