https://digital.katalog.queersearch.org/s/katalog/item/43666, “Wise Parenthood. A Practical Sequel to "Married Love". A Book for Married People”, https://digital.katalog.queersearch.org/s/katalog/item/49905, QueerSearch, accessed 1. Mai 2025, https://digital.katalog.queersearch.org/s/katalog/item/26645