Space opera (English Wikipedia)

Cerutti, Vera; Gold, H.L., eds. (October 1950). "You'll never see it in Galaxy". Galaxy Magazine. Vol. 1, no. 1. p. 163 (back cover). Retrieved 12 March 2019 – via Internet Archive.
Dozois, Gardner & Strahan, Jonathan (2007). The New Space Opera (1st ed.). New York, NY: Eos. p. 2. ISBN 9780060846756.
Bleiler, Everett F. & Bleiler, Richard J. (1990). Science-fiction, the Early Years. Kent, Ohio: Kent State University Press. pp. 147–148. ISBN 0873384164. A full description of more than 3,000 science-fiction stories from earliest times to the appearance of the genre magazines in 1930, with author, title, and motif indexes.

avclub.com (Global: 136^th place; English: 93^rd place)

Murray, Noel; Bowman, Donna (1 June 2012). "Firefly: "Serenity"". The A.V. Club. Retrieved 4 January 2021.

best-sci-fi-books.com (Global: low place; English: low place)

Livingston, Dan (14 March 2015). "23 Best Military Science Fiction Books". The Best Sci Fi Books. Retrieved 27 June 2021.

books.google.com (Global: 3^rd place; English: 3^rd place)

Pringle, David (2000). "What is this thing called space opera?". In Westfahl, Gary (ed.). Space and Beyond: The frontier theme in science fiction (1st ed.). Westport, CT: Greenwood Press. p. 36. ISBN 978-0313308468. Retrieved 24 March 2017.
Freistetter, Florian (15 April 2021). A History of the Universe in 100 Stars. Quercus. ISBN 9781529410136. Retrieved 6 November 2021.
Langford, David (2005). The Sex Column and Other Misprints. Wildside Press. pp. 167–168. ISBN 9781930997783. Retrieved 24 March 2017.
Latham, Rob (23 February 2017). Science Fiction Criticism: An anthology of essential writings. New York, NY: Bloomsbury Publishing. p. 133. ISBN 9781474248624. Retrieved 30 June 2017.
Green, Paul (14 October 2009). Encyclopedia of Weird Westerns: Supernatural and Science Fiction Elements in Novels, Pulps, Comics, Films, Television and Games. McFarland. pp. 3–4. ISBN 9780786458004. Retrieved 4 January 2021.
Bould, Mark; Butler, Andrew; Roberts, Adam; Vint, Sherryl (2009). The Routledge Companion to Science Fiction. Routledge. p. 508. ISBN 9781135228361. Retrieved 4 January 2021.

demon.co.uk (Global: 3,292^nd place; English: 2,192^nd place)

omegacom.demon.co.uk

McAuley, Paul. "Junk yard universes". Paul McAuley. Archived from the original on 7 April 2014. Retrieved 28 November 2017 – via Wayback Machine.

depauw.edu (Global: 8,469^th place; English: 5,010^th place)

Clarke, I.F. (November 1997). "Future-war fiction: The first main phase, 1871–1900". Science Fiction Studies. 24 (74). Retrieved 28 November 2017.

ew.com (Global: 35^th place; English: 31^st place)

Franch, Darren. "12 Signs It's a Joss Whedon Project". Entertainment Weekly. Archived from the original on 22 January 2014. Retrieved 4 January 2021.

jessesword.com (Global: low place; English: low place)

Sheidlower, Jesse, ed. (6 July 2008). "Planetary romance". Jesse Sheidlower. Science Fiction Citations in the Oxford English Dictionary. Archived from the original on 8 January 2008. Retrieved 24 March 2017.

midamericon.org (Global: low place; English: low place)

Stokes, Keith (January 1941). "Suggestion dept". Depts. of the interior. Le Zombie. No. 36. p. 9. Retrieved 24 March 2017 – via Mid American Conventions.

nytimes.com (Global: 7^th place; English: 7^th place)

"A First Showing for 'Star Trek' Pilot". The New York Times. 22 July 1986. p. 18. Retrieved 4 January 2021.

perry-rhodan-usa.com (Global: low place; English: low place)

Rastatt (July 1996). "Perry Rhodan 35th anniversary Press Release". Perry Rhodan English Language Homepage. Archived from the original on 30 April 2008. Retrieved 6 November 2021.

reference.com (Global: 657^th place; English: 613^th place)

dictionary.reference.com

"Space-opera". Dictionary.com. Retrieved 20 January 2016.

sfrevu.com (Global: low place; English: low place)

Hartwell, David G.; Cramer, Kathryn (August 2003). "Space opera redefined". SF Revu (review). Retrieved 8 February 2009.

strangehorizons.com (Global: low place; English: 6,763^rd place)

Lilly, Nathan E. (30 December 2009). "The Emancipation of Bat Durston, or: "I'm from Iowa, I Only Work in Outer Space"". Strange Horizons. Archived from the original on 14 March 2014. Retrieved 4 January 2021.

theguardian.com (Global: 12^th place; English: 11^th place)

Child, Ben (20 February 2017). "A modern space opera: Has Star Wars escaped the George Lucas worldview?". The Guardian. Retrieved 24 March 2017.
Walter, Damien (29 August 2014). "Space opera strikes up again for a new era". The Guardian. Retrieved 13 January 2020.

tor.com (Global: 1,483^rd place; English: 828^th place)

Britt, Ryan (28 February 2013). "How Timothy Zahn's heir to the empire turned Star Wars into science fiction". Tor.com. Archived from the original on 16 June 2015. Retrieved 24 March 2017.

web.archive.org (Global: 1^st place; English: 1^st place)

Rastatt (July 1996). "Perry Rhodan 35th anniversary Press Release". Perry Rhodan English Language Homepage. Archived from the original on 30 April 2008. Retrieved 6 November 2021.
Sheidlower, Jesse, ed. (6 July 2008). "Planetary romance". Jesse Sheidlower. Science Fiction Citations in the Oxford English Dictionary. Archived from the original on 8 January 2008. Retrieved 24 March 2017.
Britt, Ryan (28 February 2013). "How Timothy Zahn's heir to the empire turned Star Wars into science fiction". Tor.com. Archived from the original on 16 June 2015. Retrieved 24 March 2017.
McAuley, Paul. "Junk yard universes". Paul McAuley. Archived from the original on 7 April 2014. Retrieved 28 November 2017 – via Wayback Machine.
Franch, Darren. "12 Signs It's a Joss Whedon Project". Entertainment Weekly. Archived from the original on 22 January 2014. Retrieved 4 January 2021.
Lilly, Nathan E. (30 December 2009). "The Emancipation of Bat Durston, or: "I'm from Iowa, I Only Work in Outer Space"". Strange Horizons. Archived from the original on 14 March 2014. Retrieved 4 January 2021.

Space opera (English Wikipedia)

academia.edu (Global: 121st place; English: 142nd place)

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reference.com (Global: 657th place; English: 613th place)

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sfrevu.com (Global: low place; English: low place)

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theguardian.com (Global: 12th place; English: 11th place)

tor.com (Global: 1,483rd place; English: 828th place)

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academia.edu (Global: 121^st place; English: 142^nd place)

archive.org (Global: 6^th place; English: 6^th place)

avclub.com (Global: 136^th place; English: 93^rd place)

books.google.com (Global: 3^rd place; English: 3^rd place)

demon.co.uk (Global: 3,292^nd place; English: 2,192^nd place)

depauw.edu (Global: 8,469^th place; English: 5,010^th place)

ew.com (Global: 35^th place; English: 31^st place)

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reference.com (Global: 657^th place; English: 613^th place)

strangehorizons.com (Global: low place; English: 6,763^rd place)

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tor.com (Global: 1,483^rd place; English: 828^th place)

web.archive.org (Global: 1^st place; English: 1^st place)