The Unconquerable
Bill Fawcett
Bolos (2)
Unchained
C. J. Barry
Uncertainty
John W. Campbell, Jr.
Unborn Tomorrow
Mack Reynolds
Against All Enemies
Alexander C. Irvine
The Ultimates (1)
The Ultimate Wave
Terry Denton
Storymaze (1)
The Ultimate Hitchhiker's Guide to the Galaxy
Douglas Adams
Hitchhiker's Guide to the Galaxy (99)
The Ultimate Catalyst
John Taine
The Ultimate Bike Path
Mike Sirota
Bicycling Through Space and Time (2)
Ullr Uprising
H. Beam Piper
Federation (1)
Uller Uprising
Gerry Anderson's UFO 2
John Burke
Ubik
Philip K. Dick
The Tyrant
Eric Flint & David Drake
General / Raj Whitehall (8)
Tyrant's Blood
Fiona McIntosh
Valisar (2)
Tyrannosaurus Rex
J. F. Rivkin
Age of Dinosaurs (1)
The Typewriter
David H. Keller, M.D.
Two Thousand Miles Below
Charles Willard Diffin
The Two Faces of Tomorrow
James P. Hogan