12 books • 7 series
Investigating Crop Circles (World's Greatest Mysteries)
Investigating UFOs (World's Greatest Mysteries)
Eyewitness to the Assassination of Archduke Francis Ferdinand (Eyewitness to World War I)
Eyewitness to World War I Medicine (Eyewitness to World War I)
Back from Near Extinction (Set) (Back from Near Extinction)
Humpback Whale (Back from Near Extinction)
Back from Near Extinction (Back from Near Extinction)
Joplin Tornado Survival Stories (Natural Disaster True Survival Stories)
Presidential Perspectives (Presidential Perspectives)
September 11 Through the Eyes of George W. Bush (Presidential Perspectives)
UFOs (Unsolved Mysteries)
Crop Circles (Unsolved Mysteries)