The age of the pussyfoot
Frederik Pohl
Beyond the blue event horizon
Beyond the Blue Event Horizon (Heechee Saga)
Day Million
The Day of the Boomer Dukes
The Far Shore of Time
Gateway
The Hated
Heechee Rendezvous
Heechee rendezvous: a novel
Homegoing
Pythias
Star of stars
The World at the End of Time