2005, Rhiannon Bury, Cyberspaces of Their Own: Female Fandoms Online, Peter Lang (2005), ISBN0820471186, page 207:
Mary Ellen Curtin presented a paper at the 2002 Popular Culture Association conference in which she studied fanfiction archives to discover that black characters appeared far less in both het and slash fiction than white or even Latino/a characters.
2006, Catherine Driscoll, "One True Pairing: The Romance of Pornography and the Pornography of Romance", in Fan Fiction and Fan Communities in the Age of the Internet: New Essays (eds. Karen Hellekson & Kristina Busse), McFarland & Company (2006), ISBN9780786426409, page 84:
The vast majority of fan fiction is het or slash, and these types are usually defined against each other as approaches to romance and porn, marginalizing gen as something outside of the dominant concerns of fan fiction.
2009, Emily Turner, "Scary Just Got Sexy: Transgression in Supernatural and Its Fanfiction", in In the Hunt: Unauthorized Essays on Supernatural (ed. Supernatural.tv), BenBella Books (2009), ISBN9781933771632, page 157:
[…] according to the research conducted by one fan recording and analyzing the stories posted through the daily newsletter, the fanfiction in editions 1 through 600 was almost 40 percent Wincest; 37 percent “gen” (general, non-sexual or romantic stories), approximately 15 percent was “het” (stories with male/female romantic or sexual relationships), and the rest of the pie went to miscellaneous other categories.
2010, Rebecca Ward Black, "Just Don't Call Them Cartoons: The New Literacy Spaces of Anime, Manga, and Fanfiction", in Handbook of Research on New Literacies (eds. Julie Coiro, Michele Knobel, Colin Lankshear, & Donald J. Leu), Lawrence Erlbaum Associates (2010), ISBN9780805856514, page 595:
Other studies explore why some women write het, or fictions with heterosexual pairings of certain couples, within canons such as Star Trek Voyager that generally inspire slash fiction (Somogyi, 2002).
2011, Catherine Tosenberger, "Homosexuality at the Online Hogwarts: Harry Potter Slash Fanfiction", in Over the Rainbow: Queer Children's and Young Adult Literature (eds. Michelle Ann Abate & Kenneth B. Kidd), ISBN9780472071463, page 331:
As no one places a similar limitation on het fics—stories that concern canonical heterosexual pairings, such as Molly/Arthur, are still labeled “het”—most fans reason that it doesn't make sense to apply the restriction to slash.