Sons of the Ocean Deeps
Bryce Walton
The Secret of the Ninth Planet
Donald A. Wollheim
The Secret of Saturn's Rings
Secret of the Martian Moons
Mystery of the Third Mine
Robert A. W. Lowndes
Trouble on Titan
Alan E. Nourse
Stadium Beyond the Stars
Milton Lesser
Lost Race of Mars
Robert Silverberg
Step to the Stars
Lester Del Rey
Jim Stanley (1)
Mission to the Moon
Jim Stanley (2)
Son of the Stars
Raymond F. Jones
Ron Barron (1)
Planet of Light
Ron Barron (2)
The Star Conquerors
Ben Bova
Star Watch / Watchmen (1)