- Galaxy ZackRay O'Ryan
- Monsters in space!Ray O'Ryan
- Science fair disaster!Ray O'Ryan
- The Prehistoric PlanetRay O'Ryan
- The annoying crushRay O'Ryan
- A galactic Easter!Ray O'Ryan
- Return to Earth!Ray O'Ryan
- A Green Christmas! (Galaxy Zack)Ray O'Ryan
- Three's a crowd!Ray O'Ryan
- Journey To Juno (Turtleback School & Library Binding Edition) (Galaxy Zack)Ray O'Ryan
- A Haunted Halloween (Galaxy Zack)Ray O'Ryan
- Ready, Set, Blast Off! (15) (Galaxy Zack)Ray O'Ryan
- Galaxy Zack 4 Books in 1!: Hello, Nebulon!; Journey to Juno; The Prehistoric Planet; Monsters in Space!Ray O'Ryan
- Operation Twin Trouble (Turtleback School & Library Binding Edition) (Galaxy Zack)Ray O'Ryan
- Ready, Set, Blast Off!Ray O'Ryan, Jason Kraft
- The Prehistoric PlanetRay O'Ryan, Colin Jack
- A Haunted Halloween (Galaxy Zack Book 11)Ray O'Ryan
- Cosmic Blackout!Ray O'Ryan
- Space Camp (Turtleback School & Library Binding Edition) (Galaxy Zack)Ray O'Ryan
- Operation Twin Trouble (Galaxy Zack)Ray O'Ryan
