- Rain forests, a nonfiction companion to Afternoon on the Amazon, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Knights and castles, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Earthquake in the early morning, Mary Pope Osborne ; illustrated by Sal Murdocca
- Dragon of the red dawn, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Soccer, Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Dark day in the deep sea, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Tonight on the Titanic, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Season of the Sandstorms, Mary Pope Osborne
- Buffalo Before Breakfast, Mary Pope Osborne
- Leprechauns and Irish Folklore, Natalie Pope Boyce
- Leprechaun in late winter, by Mary Pope Osborne ; illustrated by Sal Murdocca
- A crazy day with cobras, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Twisters and other terrible storms, a nonfiction companion to Magic tree house #23, Twister on Tuesday, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Haunted Castle on Hallows Eve, Mary Pope Osborne
- A Good Night for Ghosts, Mary Pope Osborne
- Shadow of the shark, Mary Pope Osborne ; illustrated by Sal Murdocca
- Tonight on the Titanic, Mary Pope Osborne
- Dog heroes, a nonfiction companion to Magic tree house #46: Dogs in the dead of night, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- A good night for ghosts, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Balto of the Blue Dawn, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Stallion by starlight, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Haunted castle on Hallows Eve, by Mary Pope Osborne ; illustrated by Sal Murdocca
- High time for heroes, Mary Pope Osborne ; cover art and interior illustrations, Sal Murdocca
- Moonlight on the magic flute, a Merlin mission, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Sea Monsters, Natalie Pope Boyce
- Hurry up, Houdini!, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Season of the sandstorms, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Dogs in the dead of night, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Abe Lincoln at Last!, Mary Pope Osborne
- Dinosaurs before dark, Mary Pope Osborne ; illustrated by Sal Murdocca
- Christmas in Camelot, Mary Pope Osborne
- High Tide in Hawaii, Mary Pope Osborne
- Titanic, a nonfiction companion to Magic tree house #17: Tonight on the Titanic, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Night of the ninth dragon, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Abraham Lincoln, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Eve of the Emperor Penguin, Mary Pope Osborne
- Dog heroes, a nonfiction companion to Magic tree house #46: Dogs in the dead of night, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Leprechaun in Late Winter, Mary Pope Osborne
- A big day for baseball, by Mary Pope Osborne ; jacket illustration by Sal Murdocca ; interior illustrations by Ag Ford
- Leprechauns and irish folklore, a nonfiction companion to Leprechaun in late winter, 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
- Pilgrims, a nonfiction companion to Thanksgiving on Thursday, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Mummies and pyramids, a nonfiction companion to Magic tree house # 3, Mummies in the morning, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Dingoes at dinnertime, by Mary Pope Osborne ; illustrated by Sal Murdocca
- Viking Ships at Sunrise, Mary Pope Osborne
- Ancient Greece and the Olympics, a nonfiction companion to Hour of the Olympics, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Night of the new magicians, by Mary Pope Osborne ; illustrated by Sal Murdocca
- 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
- Ancient Greece and the Olympics, Natalie Pope Boyce
- Heroes for all times, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca