By Marion Zimmer Bradley. 1962. This Ace printing, 1979. Cover art by Steve Hickman.
By Zach Hughes (shown as Hugh Zachary on the copyright page). 1980.
By John Brunner. 1972. This edition, seventh Ballantine printing, 1982. Cover art by Murray Tinkelman. This may well be my favorite cover of any postapoc/dystopian book ever.
By William Barnwell. 1980. Volume I of The Blessing Trilogy.
By William C. Barnwell. 1981. Volume II of The Blessing Trilogy.
By William C. Barnwell. 1981. Third (and conclusion) in The Blessing Papers trilogy.
By Martin Caidin. 1987. Cover art by David Mattingly.
By Arthur C. Clarke. 1953. This edition, 3rd Pyramid, 1967.
By Morgan Llywelyn. 1993. This edition, first mass market, March 1994. Cover art by Dave Henderson.