Guns of the brothers Pike
The Brain of Graphicon (1973)
The Lost Fleet of Astranides (1974)
The Tomorrow Stairs (1974)
City of the First Time (1975)
Overself (1975)
The Paradise Zone (1975)
Slaver from the Stars (1975)
A Madness from Mars (1976) (writing as Dennis Summers)
The Bodysnatchers of Lethe (1976)
A Man from Tommorrow (1976) (writing as James Wallace)
The Night of the Deathship (1976)
Out of Earth's Deep (1976) (writing as Edward Leighton)
Plague of the Golden Rat (1976) (writing as James Wallace)
Stalker of the Worlds (1976) (writing as Dennis Summers)
Timeship to Thebes (1976)
A Light from Tomorrow (1977) (writing as Edward Leighton)
The Guardian of Krandor (1977) (writing as James Wallace)
The Hall of the Evolvulus (1977)
Lord of the Lightning (1977) (writing as Edward Leighton)
The Master of Ghosts (1977) (writing as Dennis Summers)
The Other Side of Red (1977)
The Robot in the Glass (1977) (writing as Dennis Summers)
Robotria (1977)
Earth Watch (1978)