https://digital.katalog.queersearch.org/s/katalog/item/44527, https://digital.katalog.queersearch.org/s/katalog/item/44528, and https://digital.katalog.queersearch.org/s/katalog/item/44530, “Die psychischen Heilmethoden: Für ärztliches Studium und Praxis”, https://digital.katalog.queersearch.org/s/katalog/item/47522, QueerSearch, accessed 1. Mai 2025, https://digital.katalog.queersearch.org/s/katalog/item/28232