Mysteries of History: Mystery of the Sphinx
Mysteries of History: Mystery of the Mary Celeste
Mysteries of History: Mystery of the Roanoke Colonists
Climate Change: Examining the Facts
Special Reports: Vaccination Debate
Mysteries of History: Mystery of Area 51
Deadliest Diseases of All Time: Ebola
Special Reports: Ebola Outbreak
Secret Societies and Clubs in American History
Investigating Atlantis and Other Lost Cities
The Central Intelligence Agency: An Encyclopedia of Covert Ops, Intelligence Gathering, and Spies
9/11 and the War on Terror: A Documentary and Reference Guide
Investigating Witches and Witchcraft
Investigating the Abominable Snowman and Other Legendary Beasts
Investigating Ghosts and the Spirit World
Disasters and Tragic Events: An Encyclopedia of Catastrophes in American History