41 titles- Honoré de Balzac. The Centenarian; or The Two Behringelds (New York: Arno Press, 1976)
- Robert A. Heinlein: Stranger in his Own Land (San Bernardino, California: The Borgo Press, 1976)
- The Farthest Shores of Ursula K. Le Guin (San Bernardino, California: The Borgo Press, 1976)
- Robert A. Heinlein: Stranger in his Own Land (San Bernardino, California: The Borgo Press, 1977)
- The Bradbury Chronicles (San Bernardino, California: The Borgo Press, 1977)
- The Delany Intersection: Samuel R. Delany Considered as a Writer of Semi-Precious Words (San Bernardino, California: The Borgo Press, 1977)
- Harlan Ellison: Unrepentant Harlequin (San Bernardino, California: The Borgo Press, 1977)
- The Classic Years of Robert A. Heinlein (San Bernardino, California: The Borgo Press, 1977)
- J-H Rosny aîné. The Xipehuz and The Death of the Earth (New York: Arno Press, 1978) [omni: loose trans of Les Xipéhuz (in L'Immolation
- The Space Odysseys of Arthur C. Clarke (San Bernardino, California: The Borgo Press, 1978)
- Bridges to Science Fiction (Carbondale, Illinois: Southern Illinois University Press, 1980) with George Robert Guffey and Mark Rose
- Bridges to Fantasy (Carbondale, Illinois: Southern Illinois University Press, 1982) with Eric S Rabkin and Robert Scholes
- Coordinates: Placing Science Fiction and Fantasy (Carbondale, Illinois: Southern Illinois University Press, 1983) with Eric S Rabkin and Robert Scholes
- Shadows of the Magic Lamp: Fantasy and Science Fiction in Film (Carbondale, Illinois: Southern Illinois University Press, 1985) with Eric S Rabkin
- Hard Science Fiction (Carbondale, Illinois: Southern Illinois University Press, 1986) with Eric S Rabkin
- Storm Warnings: Science Fiction Confronts the Future (Carbondale, Illinois: Southern Illinois University Press, 1987) with Colin Greenland and Eric S Rabkin
- Intersections: Fantasy and Science Fiction (Carbondale, Illinois: Southern Illinois University Press, 1987) with Eric S Rabkin
- Aliens: The Anthropology of Science Fiction (Carbondale, Illinois: Southern Illinois University Press, 1987) with Eric S Rabkin
- Mindscapes: The Geographies of Imagined Worlds (Carbondale, Illinois: Southern Illinois University Press, 1989) with Eric S Rabkin
- Fiction 2000: Cyberpunk and the Future of Narrative (Athens, Georgia: University of Georgia Press, 1992) with Tom Shippey
- Styles of Creation: Aesthetic Technique and the Creation of Fictional Worlds (Athens, Georgia: University of Georgia Press, 1993) with Eric S Rabkin
- Fights of Fancy: Armed Conflict in Science Fiction and Fantasy (Athens, Georgia: University of Georgia Press, 1993) with Eric S Rabkin
- Immortal Engines: Life Extension and Immortality in Science Fiction and Fantasy (Athens, Georgia: University of Georgia Press, 1996) with Eric S Rabkin and Gary Westfahl
- Science Fiction and Market Realities (Athens, Georgia: University of Georgia Press, 1996) with Eric S Rabkin and Gary Westfahl
- Foods of the Gods: Eating and the Eaten in Fantasy and Science Fiction (Athens, Georgia: University of Georgia Press, 1996) with Eric S Rabkin and Gary Westfahl
- The Fantastic Other: An Interface of Perspectives (Amsterdam, Holland: Rodopi, 1998) with Brett Cooke and Jaume Marti-Olivella
- Transformations of Utopia: Changing Views of the Perfect Society (New York: AMS Press, 1999) with Paul K Alkon and Roger Gaillard
- Nursery Realms: Children in the Worlds of Science Fiction, Fantasy, and Horror (Athens, Georgia: University of Georgia Press, 1999) with Gary Westfahl
- H. G. Wells's Perennial Time Machine (Athens, Georgia: University of Georgia Press, 2001) with Patrick Parrinder and Daniè Chatelain
- Science Fiction, Canonization, Marginalization, and the Academy (Westport, Connecticut: Greenwood Press, 2002) with Gary Westfahl
- Unearthly Visions: Approaches to Science Fiction and Fantasy Art (Westport, Connecticut: Greenwood Press, 2002) with Kathleen Church Plummer and Gary Westfahl
- No Cure for the Future: Disease and Medicine in Science Fiction and Fantasy (Westport, Connecticut: Greenwood Press, 2002) with Gary Westfahl
- Worlds Enough and Time: Explorations of Time in Science Fiction and Fantasy (Westport, Connecticut: Greenwood Press, 2002) with David Leiby and Gary Westfahl
- Genre at the Crossroads: The Challenge of Fantasy (Pennsylvania: Xenos Books, 2003) with Jean-Pierre Barricelli (1924-1997)
- Honoré de Balzac. The Centenarian, or, The Two Beringhelds (Middletown, Connecticut: Wesleyan University Press, 2005)
- Science Fiction and the Two Cultures: Essays on Bridging the Gap between the Sciences and the Humanities (Jefferson, North Carolina: McFarland Publishers, 2009) with Gary Westfahl
- Visions of Mars: Essays on the Red Planet in Fiction and Science (Jefferson, North Carolina: McFarland and Company, 2011) with Howard V Hendrix and Eric S Rabkin
- J-H Rosny aîné. Three Science Fiction Novellas: From Prehistory to the End of Mankind (Middletown, Connecticut: Wesleyan University Press, 2012)
- J-H Rosny aîné. Three Science Fiction Novellas: From Prehistory to the End of Mankind (Middletown, Connecticut: Wesleyan University Press, 2012)
- Gregory Benford (Urbana, Illinois: University of Illinois Press, 2014)
- Jules Verne. A Priest in 1835 (Albany, Georgia: BearManor Fiction, 2016)