- Polar bears and the Arctic, a nonfiction companion to polar bears past bedtime, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Magic Tree House survival guide, Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Lions at lunchtime, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Dolphins at daybreak, by Mary Pope Osborne ; illustrated by Sal Murdocca
- A crazy day with cobras, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Soccer on Sunday, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Tsunamis and other natural disasters, a nonfiction companion to High tide in Hawaii, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Midnight on the moon, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Magic tree house survival guide, Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Vacation under the volcano, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Twister on Tuesday, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Christmas in Camelot, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Blizzard of the blue moon, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Night of the ninth dragon, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Monday with a mad genius, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Sunset of the sabertooth, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Ancient Greece and the Olympics, a nonfiction companion to Hour of the Olympics, y Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Night of the new magicians, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Sea monsters, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Magic tricks from the tree house, a fun companion to Hurry up, Houdini!, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- High time for heroes, Mary Pope Osborne ; illustrated by Sal Murdocca
- Balto of the Blue Dawn, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Hour of the Olympics, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Shadow of the shark, Mary Pope Osborne ; illustrated by Sal Murdocca.
- Civil War on Sunday, Mary Pope Osborne ; illustrated by Sal Murdocca
- Stage fright on a summer night, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Winter of the ice wizard, by Mary Pope Osborne ; illustrated by Sal Murdocca
- A big day for baseball, by Mary Pope Osborne ; jacket illustration by Sal Murdocca ; interior illustrations by Ag Ford