The Forever War (The Forever War Series Book 1)
Forever Peace (Forever War)
The Worlds Trilogy: Worlds, Worlds Apart, and Worlds Enough and Time
The Crucible of Time
Camouflage
The Accidental Time Machine
The World of Tiers Volume Two: Behind the Walls of Terra, The Lavalite World, Red Orc's Rage, and More Than Fire
Old Man's War