https://digital.katalog.queersearch.org/s/katalog/item/47415, “Max Hodann (1894-1946): Sozialist und Sexualreformer”, https://digital.katalog.queersearch.org/s/katalog/item/49726, QueerSearch, accessed 28. April 2025, https://digital.katalog.queersearch.org/s/katalog/item/26995