Orphans of the Sky
Robert A. Heinlein
The Dark Beyond the Stars : A Novel
Frank M. Robinson
Dragon Wing (The Death Gate Cycle #1)
Margaret Weis & Tracy Hickman
Death Gate Cycle (1)
The Day of Their Return
Poul Anderson
Carpe Jugulum
Terry Pratchett
Discworld (23)
Mort
Discworld (4)
Witches Abroad
Discworld (12)
Wyrd Sisters
Discworld (6)
The Long Mars
Terry Pratchett & Stephen Baxter
The long Earth (3)