The Ringworld Engineers
Larry Niven
Ringworld (2)
City of Sorcery
Marion Zimmer Bradley
Darkover (15)
Foundation and Empire
Isaac Asimov
Foundation (4)
The Clockwise Man
Justin Richards
Daughter of the Moon (Tales of Inthya)
Effie Calvin
Tales of Inthya (5)
A Princess Who Defied Kings
J. Kirsch