https://digital.katalog.queersearch.org/s/katalog/item/43666, “Wise Parenthood: The Treatise on Birth Control for Married People. A Practical Sequel to "Married Love"”, https://digital.katalog.queersearch.org/s/katalog/item/49905, QueerSearch, accessed 1. Mai 2025, https://digital.katalog.queersearch.org/s/katalog/item/26655