Laumer, Keith
Chronological Checklist
Series – Imperium
- Worlds of the Imperium (New York: Ace Books, 1962)
- The Other Side of Time (New York: Berkley Books, 1965)
- Assignment in Nowhere (New York: Berkley Books, 1968)
- Beyond the Imperium (New York: Tor, 1981)
- Worlds of the Imperium: Special Bonus Stories "The War Against the Yukks" and "Worldmaster" (New York: Tor, 1982)
- Zone Yellow: An Imperium Novel (New York: Baen Books, 1990)
- Imperium (New York: Baen Books, 2005)