16 books • 11 series
Code Breakers and Spies of the Vietnam War (Code Breakers and Spies)
Code Breakers and Spies of the Civil War (Code Breakers and Spies)
The Hope Diamond, Cursed Objects, and Unexplained Artifacts (Paranormal Investigations)
Mass Government Surveillance (Spying, Surveillance, and Privacy in the 21st-Century)
The Bermuda Triangle, Stonehenge, and Unexplained Places (Paranormal Investigations)
Aliens, Ufos, and Unexplained Encounters (Paranormal Investigations)
Davy Crockett: Frontiersman (American Legends and Folktales (Group 3))
Martyrdom: Christians in the Roman Empire (Public Persecutions)
Strategic Inventions of the Crusades (Tech in the Trenches (Group 2))
Thomas Jefferson (Great American Thinkers)
Henry David Thoreau (Great American Thinkers)
Germany (Exploring World Cultures)
Life as a Child Laborer During the Industrial Revolution (Life as)
Demons (Creatues of Fantasy)
Aliens (Creatues of Fantasy)
Ghosts (Creatures of Fantasy)