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