WtO
Shadow Player's Guide (1997)
Traitor's Manual
Mongoose Publishing
The Nightmare Switch
Unknown
Dragon Magazine #381
Ringworld 4 - Ringworld's Children
Larry Niven
Ringworld (4)
Ringworld 1 - Ringworld
Ringworld (1)
Ringworld 2 - Ringworld Engineers
Ringworld (2)
Ringworld 3 - The Ringworld Throne
Ringworld (3)