https://digital.katalog.queersearch.org/s/katalog/item/45038 and https://digital.katalog.queersearch.org/s/katalog/item/45039, “Im Auge des Exils: Josef Breitenbach und die Freie Deutsche Kultur in Paris 1933-1941”, https://digital.katalog.queersearch.org/s/katalog/item/42678, QueerSearch, accessed 15. Mai 2025, https://digital.katalog.queersearch.org/s/katalog/item/29459