This listing is for the following books:

Assorted Authors:

Imperial Stars 1: The Stars at War

Robots

The Communipaths/The Noblest Experiment in the Galaxy

Bob Shaw:

Orbitsville Departure*

Christopher Rowley:

The War for Eternity*

Eric Frank Russell:

Sinister Barrier

The Best of Eric Frank Russell

Fred Saberhagen:

The Mask of the Sun

H. F. Saint:

Memoirs of an Invisible Man

J.D. Masters:

Steele

Keith Laumer:

The Ultimax Man*

Kurt Mahr:

Perry Rhodan 10: The Ghosts of Gol

L. Ron Hubbard:

Battlefield Earth*

Mission Earth 1: The Invaders Plan

Mack Reynolds and Michael Banks:

Joe Mauser Mercenary from Tomorrow

Melisa C. Michaels:

Pirate Prince*

Mike Resnick:

Santiago

Paul Preuss:

Starfire*

Peter David:

Star Trek New Frontier Excalibur Requiem

Star Trek The Next Generation Vendetta*

Roberty Doherty:

Area 51 The Sphinx*

Stephen Robinett:

Projections

Wen Spencer:

Endless Blue

The Communipaths/The Noblest Experiment in the Galaxy is a double feature.

These books are all used.  The conditions of the books vary, but all are readable.  The starred books are in the worst condition.  Spine stress and yellowing seem to be the most common problems.  Area 51 The Sphinx is a former library book.

All of these books are in English.