- Magic tree house, adapted by Jenny Laird ; with art by Kelly & Nichole Matthews, 5
- Magic tree house, Mary Pope Osborne, Books 46 &47
- Titanic :, a nonfiction companion to Tonight on the Titanic, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Thanksgiving ;, Thanksgiving on Thursday ; Pilgrims : a nonfiction companion to Thanksgiving on Thursday, Mary Pope Osborne ; Natalie Pope Boyce
- Magic tree house, Mary Pope Osborne, Books 48 & 49
- Leonardo da Vinci :, a nonfiction companion to Monday with a mad genius, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Ancient Rome and Pompeii :, a nonfiction companion to Vacation under the volcano, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Danger in the darkest hour, Mary Pope Osborne
- Twisters and other terrible storms :, a nonfiction companion to Twister on Tuesday, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Vikings, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari
- Magic tree house, Mary Pope Osborne, Books 40 & 41
- Space :, a nonfiction companion to Midnight on the moon, by Will Osborne and Mary Pope Osborne ; illlustrated by Sal Murdocca
- Snakes and other reptiles :, a nonfiction companion to A crazy day with cobras, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Magic tree house, Mary Pope Osborne, Books 50 & 51
- Pirates :, Pirates past noon ; Pirates : a nonfiction companion to Pirates past noon, by Mary Pope Osborne ; illustrated by Sal Murdocca ; Will Osborne
- American revolution :, a nonfiction companion to Revolutionary War on Wednesday, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Knights and castles :, a nonfiction companion to The knight at dawn, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Sabertooths and the ice age :, a nonfiction companion to Magic tree house #7: Sunset of the sabertooth, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Magic tree house, adapted by Jenny Laird ; with art by Kelly & Nichole Matthews, 2
- Pilgrims, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Penguins :, Eve of the Emperor penguin ; Penguins and Antarctica : a nonfiction companion to Eve of the Emperor penguins, Sal Murdocca
- Fourteen days :, a literary project of the Authors Guild of America, edited by Margaret Atwood and Douglas Preston
- Dinosaurs :, Dinosaurs before dark ; Dinosaurs : a nonfiction companion to Dinosaurs before dark, Mary Pope Osborne ; Will Osborne ; Sal Murdocca
- Rain forests :, a nonfiction companion to Afternoon on the Amazon, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Magic tree house, Mary Pope Osborne, Books 52-53
- Horses :, Stallion by starlight ; Horse heroes, by Mary Pope Osborne and Natalie Pope Boyce
- Ninjas :, Night of the Ninjas ; Ninjas and samurai : a nonfiction companion to Night of the Ninjas, by Mary Pope Osborne ; illustrated by Sal Murdocca ; Will Osborne
- Soccer :, Soccer on Sunday ; Soccer : a nonfiction companion to Soccer on Sunday, Mary Pope Osborne ; Natalie Pope Boyce
- Dinosaurs, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Mummies :, Mummies in the morning ; Mummies and pyramids : a nonfiction companion to Mummies in the morning, by Mary Pope Osborne ; illustrated by Sal Murdocca ; Will Osborne
- 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
- Pirates :, a nonfiction companion to Pirates past noon, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Dogsledding and extreme sports, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari
- Sea monsters, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Magic tree house, adapted by Jenny Laird ; with art by Kelly & Nichole Matthews, 4
- China :, land of the emperor's Great Wall, Natalie Pope Boyce
- Soccer :, a nonfiction companion to Soccer on Sunday, Mary Pope Osborne and Natalie Pope Boyce
- Magic tree house, adapted by Jenny Laird ; with art by Kelly & Nichole Matthews, 1
- Rags and riches :, kids in the time of Charles Dickens, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Wild West :, a nonfiction companion to Magic tree house #10 : Ghost town at sundown/, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Isidre Monés
- World War II :, a nonfiction companion to Magic tree house super edition #1 : World at war, 1944, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Carlo Molinari
- 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
- Knights :, The knight at dawn ; Knights and castles : a nonfiction companion to The knight at dawn, by Mary Pope Osborne ; Will Osborne ; illustrated by Sal Murdocca
- Magic tree house, adapted by Jenny Laird ; with art by Kelly & Nichole Matthews, 3
- Dolphins and sharks :, a nonfiction companion to Magic tree house #9 : Dolphins at daybreak, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- Magic tricks from the tree house :, a fun companion to Magic Tree House #50 : hurry up, Houdini!, by Mary Pope Osborne and Natalie Pope Boyce ; illustrated by Sal Murdocca
- 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
- Charles Dickens :, A ghost tale for Christmas time ; Rags and riches : kids in the time of Charles Dickens, Mary Pope Osborne, Natalie Pope Boyce
- Mummies and pyramids :, a nonfiction companion to Mummies in the morning, by Will Osborne and Mary Pope Osborne ; illustrated by Sal Murdocca
- Balto of the blue dawn ;, Night of the ninth dragon, Mary Pope Osborne