https://digital.katalog.queersearch.org/s/katalog/item/43419, “Hilleriana aus dem Nachlass von Hans-Günter Klein: [Lochhefter]”, https://digital.katalog.queersearch.org/s/katalog/item/48942, QueerSearch, accessed 30. April 2025, https://digital.katalog.queersearch.org/s/katalog/item/26189