1. American Psychological Association (2008). Answers to your questions: for a better understanding of sexual orientation and homosexuality. Washington: APA.
2. Baldaro Verde J., Todella R. (2006). Luci e ombre nella coppia di oggi. Analisi dei mutamenti nelle relazioni tra uomini e donne. Milano: FrancoAngeli.
3. Three-year follow-up of same-sex couples who had civil unions in Vermont, same-sex couples not in civil unions, and heterosexual married couples.
4. Bancroft J. (2009). Human sexuality and its problems. New York: Churchill Livingstone Elsevier.
5. Barbagli M., Colombo A. (2007). Omosessuali moderni. Gay e lesbiche in Italia. Bologna: Il Mulino.