84 books • 15 series
Hotshot Crews
Smokejumpers
Ligue 1 (Soccer Leagues)
National Women's Soccer League (Soccer Leagues)
La Liga (Soccer Leagues)
Triatlón
Cycling
Esgrima
Fencing
Ciclismo
Triathlon
Athletics
Atletismo
Burj Khalifa
Channel Tunnel
Hoover Dam
MOBA Games
Hottest Habitats
Strangest Senses
Fighting Games
Roanoke Colony (Unsolved Mysteries)
Irish Crown Jewels Theft (Unsolved Mysteries)
Taj Mahal (Structural Wonders)
Vitamins as Necessary Nutrients (Necessary Nutrients)