https://digital.katalog.queersearch.org/s/katalog/item/65231 and https://digital.katalog.queersearch.org/s/katalog/item/65232, “Partner Homogamy in Married, Heterosexual Cohabiting, Gay, and Lesbian Couples”, QueerSearch, accessed 2. Juli 2025, https://digital.katalog.queersearch.org/s/katalog/item/61377