Mysteries of History: Mystery of Area 51
Mysteries of History: Mystery of the Nazca Lines
Mysteries of History: Mystery of Atlantis
Mysteries of History: Mystery of the Sphinx
Special Reports: Vaccination Debate
Special Reports: Ebola Outbreak
Deadliest Diseases of All Time: Ebola
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 Witches and Witchcraft
Investigating Atlantis and Other Lost Cities
Secret Societies and Clubs in American History
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