Mah, Kenneth; Binik, Yitzchak M «The nature of human orgasm: a critical review of major trends». Clinical Psychology Review, 21, 6, 07-01-2001, pàg. 823–856. DOI: 10.1016/S0272-7358(00)00069-6. PMID: 11497209. «Women rated clitoral stimulation as at least somewhat more important than vaginal stimulation in achieving orgasm; only about 20% indicated that they did not require additional clitoral stimulation during intercourse.»
Kammerer-Doak, Dorothy; Rogers, Rebecca G. «Female Sexual Function and Dysfunction». Obstetrics and Gynecology Clinics of North America, 35, 2, 6-2008, pàg. 169–183. DOI: 10.1016/j.ogc.2008.03.006. PMID: 18486835. «Most women report the inability to achieve orgasm with vaginal intercourse and require direct clitoral stimulation ... About 20% have coital climaxes...»
Pina-Cabral, Joao de «Tamed Violence: Genital Symbolism is Portuguese popular culture». Man, 28, 1, 1992, pàg. 101–120. DOI: 10.2307/2804438. JSTOR: 2804438.
Vegeu aqui i pages 47-49 per a la virginitat masculina, de com defineixen les persones homosexuals i lesbianes la pèrdua de virginitat i com la majoria d'investigadors i heterosexuals defineixen la pèrdua de virginitat o la “virginitat tècnica” per si una persona ha participat o no en sexe vaginal.Vegeu Laura M. Carpenter. Virginity lost: An Intimate Portrait of First Sexual Experiences. NYU Press, 2005, p. 295 pages. ISBN 0-8147-1652-0 [Consulta: 9 octubre 2011].
The Marriage and Family Experience: Intimate Relationship in a Changing Society. Cengage Learning, 2010, p. 186. ISBN 0-534-62425-1 [Consulta: 8 octubre 2011]. «La majoria de les persones estan d'acord que mantenim la virginitat sempre que ens abstinguem de tenir relacions sexuals (vaginals). Però de tant en tant sentim la gent que parla de "virginitat tècnica" […] Les dades indiquen que "una proporció molt significativa dels adolescents, ha tingut experiència amb el sexe oral, encara que no han tingut relacions sexuals, i poden considerar-se a si mateixos com verges '[…] una altra investigació, especialment la investigació que mira a la pèrdua de la virginitat, informa que el 35% de les verges, que es defineixen com les persones que mai han participat en les relacions sexuals vaginals, però, han participat en una o més d'altres formes d'activitat sexual heterosexual (per exemple, sexe oral, sexe anal, o la masturbació mútua).»
Jesse Bering, "So Close, and Yet So Far Away: The Contorted History of Autofellatio", in Why Is the Penis Shaped Like That?: And Other Reflections on Being Human, New York: Scientific American / Farrar, Straus, Giroux, 2012, ISBN 9780374532925, pp. 11–16, p. 16.
Drawing, Art of Love: Nearly 100 Sex Positions and Wealth of Illustrated Material from Foreplay to Anatomy, e-book, Mobilereference.com, 2007, ISBN 9781605011172, n.p.[Enllaç no actiu]
Ken Plummer. Modern Homosexualities: Fragments of Lesbian and Gay Experiences. Routledge, 2002, p. 187–191. ISBN 1134922426 [Consulta: 24 agost 2013]. «The social construction of 'sex' as vaginal intercourse affects how other forms of sexual activity are evaluated as sexually satisfying or arousing; in some cases whether an activity is seen as a sexual act at all. For example, unless a woman has been penetrated by a man's penis she is still technically a virgin even if she has had lots of sexual experience.»
Mah, Kenneth; Binik, Yitzchak M «The nature of human orgasm: a critical review of major trends». Clinical Psychology Review, 21, 6, 07-01-2001, pàg. 823–856. DOI: 10.1016/S0272-7358(00)00069-6. PMID: 11497209. «Women rated clitoral stimulation as at least somewhat more important than vaginal stimulation in achieving orgasm; only about 20% indicated that they did not require additional clitoral stimulation during intercourse.»
Kammerer-Doak, Dorothy; Rogers, Rebecca G. «Female Sexual Function and Dysfunction». Obstetrics and Gynecology Clinics of North America, 35, 2, 6-2008, pàg. 169–183. DOI: 10.1016/j.ogc.2008.03.006. PMID: 18486835. «Most women report the inability to achieve orgasm with vaginal intercourse and require direct clitoral stimulation ... About 20% have coital climaxes...»