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)
The Bodysnatchers of Lethe (1976)
A Madness from Mars (1976) (writing as Dennis Summers)
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)
The Guardian of Krandor (1977) (writing as James Wallace)
The Hall of the Evolvulus (1977)
A Light from Tomorrow (1977) (writing as Edward Leighton)
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)