Michael W. Ross, Lorna D. Channon-Little, B. R. Simon Rosser (2000). Sexual Health Concerns: Interviewing and History Taking for Health Practitioners. University of Michigan. p.45. ISBN0803606680.{{cite book}}: CS1 maint: uses authors parameter (ลิงก์)CS1 maint: Uses authors parameter (link)
See 272 and page 301 for two different definitions of outercourse (first of the pages for no-penetration definition; second of the pages for no-penile-penetration definition). Rosenthal, Martha (2012). Human Sexuality: From Cells to Society, 1st ed. Cengage Learning. pp.576 pages. ISBN0618755713. สืบค้นเมื่อ September 17, 2012.
Robert Crooks; Karla Baur (2010). Our Sexuality. Cengage Learning. pp.286–289. ISBN0495812943. สืบค้นเมื่อ August 30, 2012. Noncoital forms of sexual intimacy, which have been called outercourse, can be a viable form of birth control. Outercourse includes all avenues of sexual intimacy other than penile–vaginal intercourse, including kissing, touching, mutual masturbation, and oral and anal sex.
See here onwards and pages 47-49 for views on what constitutes virginity loss and therefore sexual intercourse or other sexual activity; source discusses how gay and lesbian individuals define virginity loss, and how the majority of researchers and heterosexuals define virginity loss/"technical virginity" by whether or not a person has engaged in penile-vaginal sex. {{cite book}}: Citation ว่างเปล่า (help)
Bryan Strong; Christine DeVault; Theodore F. Cohen (2010). The Marriage and Family Experience: Intimate Relationship in a Changing Society. Cengage Learning. p.186. ISBN0-534-62425-1. สืบค้นเมื่อ October 8, 2011. Most people agree that we maintain virginity as long as we refrain from sexual (vaginal) intercourse. But occasionally we hear people speak of 'technical virginity' [...] Data indicate that 'a very significant proportion of teens ha[ve] had experience with oral sex, even if they haven't had sexual intercourse, and may think of themselves as virgins' [...] Other research, especially research looking into virginity loss, reports that 35% of virgins, defined as people who have never engaged in vaginal intercourse, have nonetheless engaged in one or more other forms of heterosexual sexual activity (e.g., oral sex, anal sex, or mutual masturbation).
Boston Women's Health Book Collective, Judy Norsigian (2008). Our Bodies, Ourselves: Menopause. Simon & Schuster. p.143. ISBN1439103437. สืบค้นเมื่อ September 1, 2013. For some women, outercourse, defined as lovemaking without vaginal or anal penetration...{{cite book}}: CS1 maint: uses authors parameter (ลิงก์)
Richard Blonna, Janice Loschiavo, Dan Watter (2011). Health Counseling: A Microskills Approach for Counselors, Educators, and School Nurses. Jones & Bartlett Learning. pp.170–171. ISBN0763781568. สืบค้นเมื่อ September 1, 2013. [N]onpenetrative sexual pleasure. This group of methods, sometimes called outercourse, provides options for the satisfaction of sexual desire and orgasm that do not involve the penis penetrating the vagina.{{cite book}}: CS1 maint: uses authors parameter (ลิงก์)
Lois White, Gena Duncan, Wendy Baumle (2011). Medical Surgical Nursing: An Integrated Approach, 3rd ed. Cengage Learning. p.1161. ISBN1133707149. สืบค้นเมื่อ September 1, 2013. Some people consider outercourse to mean sex play without vaginal intercourse, while others consider this to mean sex play with no penetration at all (vaginal, oral, or anal).{{cite book}}: CS1 maint: uses authors parameter (ลิงก์)
M., Hodge; Evelyn Blackwood; Jeffrey M. Dickemann; Doug Jones; Frank Muscarella; Paul L. Vasey; Walter L. Williams (2000). "The Evolution of Human Homosexual Behavior". Current Anthropology. 41: 385–413. doi:10.1086/300145. PMID10768881.
Mutual Masturbation - A biographical collection of personal data for a psychological and sociological study of mutual masturbating as it relates to the habits for both men and women.