- Magic tricks from the tree house, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Dogsledding and extreme sports, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari
- Wild West, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Isidre Monés
- Incredible fact book, Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Soccer, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Sea monsters, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Warriors, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Isidre Monés
- Heroes for all times, a nonfiction companion to Magic tree house #51: high time for heroes, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Baseball, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari
- Benjamin Franklin, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Isidre Monés
- Survival guide, Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Dragons and mythical creatures, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari
- Vikings, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari
- Ninjas and samurai, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Narwhals and other whales, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Isidre Monés
- Penguins and Antarctica, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Snakes and other reptiles, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Llamas and the Andes, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Isidre Monés
- China, land of the emperor's Great Wall, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari