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