https://digital.katalog.queersearch.org/s/katalog/item/43480, “Männerbekanntschaften. Freimütige Protokolle”, https://digital.katalog.queersearch.org/s/katalog/item/49757, QueerSearch, accessed 30. April 2025, https://digital.katalog.queersearch.org/s/katalog/item/26289