- "Alternate History: the How-to of What Might Have Been," Writer's Workshop of Science Fiction & Fantasy, edited by Michael Knost, Seventh Star Press, 2013; Reprinted in We Install, OpenRoadMedia, 8/15.
- "Catherine Crook de Camp: An Appreciation," Locus
- editor and translator, The Chronicle of Theophanes, University of Pennsylvania Press, 1982.
- "The Date of Composition of the Historia Syntomos of Patriarch Nikephoros," Byzantina kai Metabyzantina, 4: Byzantine Studies in Honor of Milton Anastos. Malibu, 1985. 91-94.
- Essay on writing How Few Remain, SFWA Bulletin Summer 1999.
- with Mary D. Martin, Patricia Cabrera and Joseph F. Payne. The Green Book: A Manual for School Districts on Developing Proposals for Special Funding. Los Angeles, 1984.
- "Historical Realism, or, Oh My God, Not Another Movement," OtherRealms Fall 1987.
- "How I Do What I Do," SFWA Bulletin, Summer 1998
- "How the Worldwar Series Came to Be," ScF News: Crystal Tower Issue 1, 8/95.
- The Immediate Successors of Justinian: A Study of the Persian Problem and of Continuity and Change in Internal Secular Affairs in the Later Roman Empire During the Reigns of Justin II and Tiberius II Constantine (A.D. 565-582), Unpublished Dissertation, University of California 1977.
- "Hox in Box," The Bulletin, Spring 2000.
- "Introduction," The Arrows of Hercules, by L. Sprague de Camp, Arc Manor Press, 2014.
- "Introduction," The Bronze God, by L. Sprague de Camp, Arc Manor Press, 2013.
- "Introduction," Charlemagne by Charles Lamb, 2001
- "Introduction," The Dragon of the Ishtar Gate, by L. Sprague de Camp, Arc Manor Press, 2013.
- "Introduction," An Elephant for Aristotle, by L. Sprague de Camp, Arc Manor Press, 2013.
- "Introduction," The Golden Wind, by L. Sprague de Camp, Arc Manor Press, 2014.
- "Introduction," If the South Had Won the Civil War, by MacKinlay Kantor, Tor 2001
- "Introduction,"Lest Darkness Fall & To Bring the Light, by L. Sprague de Camp & David Drake, Baen 1996.
- "Introduction," The Lost Continent: The Story of Atlantis, by C.J. Cutcliffe Hyne, Bison Books, 2002.
- "Introduction," Surrounded by Enemies, by Bryce Zabel, Mill City Press, 2013.
- "Justin II's Observance of Justinian's Persian Treaty of 562," Byzantinische Zeitschrift 76:2 (1983), pp.292-301.
- "L. Sprague de Camp: An Appreciation," Locus 12/00.
- "Leigh Brackett," Lorelei of the Red Mist, by Leigh Brackett, Haffner Press, 2007.
- editor, "Meeting with a King of Axum," Ancient African Civilizations: Kush and Axum, edited by Stanley Burstein, Markus Weiner Publications, 1997.
- "Occam's Razor and The Subtle Knife," Navigating the Golden Compass, edited by Glenn Yeffeth, Benbella Books, 2005
- "Perspectives on Hanukkah," "Hanukkah Lights," National Public Radio, 12/9/01; printed in We Install, OpenRoadMedia, 8/15.
- "Poul Anderson," Locus 9/01.
- with Laura Turtledove, "Pros and Cons of Being a Writer Couple," SFWA Bulletin Winter 1992.
- "The Ring and I," Meditations on Middle-Earth, edited by Karen Haber, St. Martin's Press, 2001. Reprinted in We Install, OpenRoadMedia, 8/15.
- "Samaritans, Jews, and Pagans during the Reigns of Justin II and Tiberius II Constantine," Byzantine Studies Series NS, vol 1 (1996/97), 162-178.
- with Geoffrey Landis and John Barnes, "Science: Looking Backward, One Must Be as Forward Thinking As When Looking at the Future," Science Fiction Age, 9/99.
- "Thank You," Requiem, edited by Yoji Kondo, Tor 1992.
- "This is Where I Came In," Imperium, by Keith Laumer, Baen, 2005
- "The True Size of a Post-Justiniac Army," Byzantine Studies/Etudes byzantines 10 (1983), 216-22.
- "Why I Write..." Publisher's Weekly,